HELIO, INC. NOTE PURCHASE AND SECURITY AGREEMENT AND GUARANTY July 23, 2007

Exhibit 10.1

HELIO, INC.

NOTE PURCHASE AND SECURITY AGREEMENT AND GUARANTY

July 23, 2007

TABLE OF CONTENTS

i

ii

NOTE PURCHASE AND SECURITY AGREEMENT AND GUARANTY

THIS NOTE PURCHASE AND SECURITY AGREEMENT AND GUARANTY (“ Agreement ”) is made as of July 23, 2007, by and among HELIO, Inc., a Delaware corporation (the “ Company ”), HELIO LLC, a Delaware limited liability company (the “ Guarantor, ” and together with the Company, collectively, the “ Note Parties ”, and individually, a “ Note Party ”) and EarthLink, Inc. a Delaware corporation (“ EarthLink ”), and SK Telecom USA Holdings, Inc., a Delaware corporation (“ SKT USA, ” and together with EarthLink, collectively, the “ Lenders ”, and individually, a “ Lender ”). Capitalized terms not otherwise defined in this Agreement shall have the meaning ascribed to them in Section 1 below.

WHEREAS , each of the Lenders intends to provide certain Consideration to the Company in connection with each Lender’s Commitment;

WHEREAS , the parties wish to provide for the sale and issuance of Notes in return for the provision by the Lenders of the Consideration to the Company; and

WHEREAS , the parties intend for the Company to issue in return for the Consideration one or more secured promissory notes.

NOW, THEREFORE, THE PARTIES HEREBY AGREE AS FOLLOWS :

1. Definitions .

(a) “ Act ” shall mean the Securities Act of 1933, as amended.

(b) “ Bankruptcy Code ” shall mean Title 11 of the United States Code entitled “Bankruptcy”, as now and hereafter in effect, or any successor statute.

(c) “ Business Day ” shall mean any day excluding Saturday, Sunday and any day which is a legal holiday under the laws of the State of Georgia or the State of California or is a day on which banking institutions located in such state are authorized or required by law or other governmental action to close.

(d) “ Commitment ” shall mean the commitment of a Lender to purchase any Note and “ Commitments ” shall mean such commitments of all Lenders in the aggregate. The amount of each Lender’s Commitment shall be set forth in a Purchase Notice. The maximum aggregate amount of the Commitments as of the Closing Date is $200,000,000.

(e) “ Consideration ” shall mean the amount of money to be paid by each Lender on each Purchase Date for the Notes in accordance with such Lender’s Commitment. The total Consideration to be paid by each Lender for Notes issued by the Company hereunder shall not exceed $100,000,000.

(f) “ Corporate Transaction ” shall mean (A) the closing of the sale, transfer or other disposition of all or substantially all of the Company’s and the Guarantor’s

(taken as a whole) assets, (B) the consummation of the merger or consolidation of the Company or the Guarantor with or into another entity (except a merger or consolidation in which any of the holders of capital stock of the Company or equity interests in the Guarantor immediately prior to such merger or consolidation continue to hold at least 50% of the voting power of the capital stock of the Company or the surviving or acquiring entity), (C) the closing of the transfer (whether by merger, consolidation or otherwise), in one transaction or a series of related transactions, to a person or group of affiliated persons (other than EarthLink, SKT USA or an underwriter of the Company’s or the Guarantor’s securities), of the Company’s or the Guarantor’s securities if, after such closing, such person or group of affiliated persons would hold 50% or more of the outstanding voting securities of the Company and the Guarantor (or the surviving or acquiring entity) or (D) a liquidation, dissolution or winding up of the Company or the Guarantor; provided, however, that a transaction shall not constitute a Corporate Transaction if its primary purpose is (a) to change the state of the Company’s or the Guarantor’s incorporation or (b) to create a holding company or other organization that will be owned or controlled by the persons (or affiliates of such persons) who held the Company’s securities immediately prior to such transaction in the aggregate.

(g) “ Default ” shall mean a condition or event that, after notice or lapse of time or both, would constitute an Event of Default.

(h) “ Governmental Authority ” shall mean any federal, state, provincial, municipal, national or other government, governmental department, commission, board, bureau, court, tribunal, agency or instrumentality or political subdivision thereof or any entity, officer or examiner exercising executive, legislative, judicial, regulatory or administrative functions of or pertaining to any government or any court, in each case whether associated with a state of the United States, the United States, or a foreign entity or government.

(i) “ Guaranty ” shall mean the guaranty of Guarantor set forth in Section 13.

(j) “ HELIO Loan ” shall mean the loan made by the Company to Guarantor evidenced by the Helio Note.

(k) “ HELIO Note ” shall mean the certain promissory note or notes in the principal face amount equal to the aggregate Commitments of the Lenders not to exceed $200,000,000, executed by the Guarantor in favor of the Company, together with any and all amendments or modifications thereto and any and all extensions, renewals or replacements thereof.

(l) “ Lien ” shall mean any lien, mortgage, pledge, assignment, security interest, charge or encumbrance of any kind (including any agreement to give any of the foregoing, any conditional sale or other title retention agreement, and any lease in the nature thereof) and any option, trust or other preferential arrangement having the practical effect of any of the foregoing.

(m) “ Material Adverse Effect ” shall mean (i) a material adverse effect on and/or material adverse developments with respect to the business, operations, properties,

2

assets or condition (financial or otherwise) of the Company and Guarantor taken as a whole; (ii) a material impairment of the ability of the Note Parties to fully and timely perform their Obligations; (iii) a material adverse effect on and/or material adverse developments with respect to the legality, validity, binding effect or enforceability against a Note Party of a Note Document to which it is a party; or (iv) a material impairment of the rights, remedies and benefits available to, or conferred upon, Lenders under any Note Document.

(n) “ Maturity Date ” shall mean the earlier of (i) July 23, 2010; and (ii) the date that all Obligations shall become due and payable in full hereunder and under the Notes, whether by acceleration or otherwise.

(o) “ Maximum Note Amount ” shall mean Two Hundred Million Dollars ($200,000,000).

(p) “ Note ” and “ Notes ” shall mean the secured promissory notes issued to each Lender pursuant to Section 2 below, the form of which is attached hereto as Exhibit B .

(q) “ Note Availability Period ” shall mean the period commencing on the date hereof and ending on July 23, 2008.

(r) “ Note Documents ” shall mean this Agreement, the Notes and all other documents, instruments or agreements executed and delivered by a Note Party for the benefit of Lenders in connection herewith and therewith.

(s) “ Note Exposure ” shall mean, with respect to any Lender, as of any date of determination, the outstanding principal amount of the Notes purchased by such Lender plus during the Note Availability Period, the unfunded Commitment of such Lender.

(t) “ Obligations ” shall mean all obligations of every nature of the Note Parties under any Note Document, whether for principal, interest (including interest which, but for the filing of a petition in bankruptcy with respect to any Note Party, would have accrued on any Obligation, whether or not a claim is allowed against such Note Party for such interest in the related bankruptcy proceeding), fees, expenses, indemnification or otherwise.

(u) “ Person ” shall mean and include natural persons, corporations, limited partnerships, general partnerships, limited liability companies, unlimited liability companies, limited liability partnerships, joint stock companies, joint ventures, associations, companies, trusts, banks, trust companies, land trusts, business trusts or other organizations, whether or not legal entities, and Governmental Authorities.

(v) “ Pro Rata Share ” shall mean the percentage obtained by dividing (a) the Note Exposure of a Lender by (b) the aggregate Note Exposure of all Lenders.

(w) “ Purchase Date ” shall mean the date on which the Lenders purchase Notes as specified in a Purchase Notice.

3

(x) “ Purchase Notice ” shall mean a notice substantially in the form of Exhibit C .

(y) “ UCC ” shall mean the Uniform Commercial Code as in effect from time to time in the State of Georgia or, when the context implies, the Uniform Commercial Code as in effect from time to time in any other applicable jurisdiction.

(z) “ United States ” shall mean the United States of America.

2. Purchase and Sale of Notes .

2.1 Issuance of Notes . During the Note Availability Period, in return for the Consideration paid by each Lender and subject to the terms and conditions hereof, the Company shall sell and issue to such Lender, and such Lender shall purchase from the Company, Notes in an aggregate principal amount up to but not exceeding such Lender’s Commitment provided that after giving effect to the purchase of any Notes in no event shall the aggregate principal amount of Notes purchased and sold hereunder exceed the Maximum Note Amount. All amounts owed by the Company pursuant to the Notes shall be paid in full no later than the Maturity Date.

2.2 Purchase Date and Closing Mechanics .

(a) On each Purchase Date that the Company desires Lenders to purchase Notes, the Company shall deliver to each Lender a fully executed and delivered Purchase Notice no later than 11:00 a.m. (eastern standard time) at least three Business Day in advance of the proposed Purchase Date. Notes shall only be purchased by Lenders on a Purchase Date and the Note purchased by each Lender on such Purchase Date shall be equal to such Lender’s Pro Rata Share of the amount set forth in the Purchase Notice.

(b) The closing of the purchase of the Notes by Lenders on each Purchase Date (each such date a “ Closing Date ”) in return for the Consideration paid by each Lender shall take place at the offices of the Company, at the executive offices of the Company or at such other place as the Company and the Lenders agree upon orally or in writing. On each Closing Date, provided the conditions precedent specified herein have been satisfied or waived, the Lenders shall purchase their Pro Rata Share of the Commitments requested to be purchased by the Company pursuant to the applicable Purchase Notice. On such date, each Lender shall deliver the Consideration with respect to the Notes to be purchased by such Lender on such Purchase Date to the Company and the Company shall deliver to each Lender one or more executed Notes in return for the respective Consideration provided to the Company.

(c) Upon the purchase by Lenders of Notes on a Purchase Date, at the close of business on such Purchase Date, the Commitment of each Lender hereunder shall be reduced by the amount of such Lender’s Commitment as set forth in the applicable Purchase Notice for such Purchase Date.

2.3 Use of Proceeds . The proceeds of each Note shall be used by the Company for the sole purpose of making a loan to Guarantor pursuant to the Helio Loan. Guarantor shall use the proceeds of such loan for the limited purpose to finance Guarantor’s (i) working capital requirements and (ii) product development expenses.

4

2.4 Obligations Several; Independent Nature of Lenders’ Rights .

(a) The obligations of Lenders hereunder are several and no Lender shall be responsible for the obligations or Commitment of any other Lender hereunder.

(b) Each Lender shall purchase Notes hereunder according to its Pro Rata Share of the Commitments and the Company shall make each payment or prepayment of principal of the Notes or of interest on the Notes to the Lenders in accordance with their Pro Rata Share of the Commitments.

(c) Nothing contained herein or in any other Note Document, and no action taken by Lenders pursuant hereto or thereto, shall be deemed to constitute Lenders as a partnership, an association, a joint venture or any other kind of entity. The amounts payable at any time hereunder to each Lender shall be a separate and independent debt, and each Lender shall be entitled to protect and enforce its rights arising out hereof and it shall not be necessary for any other Lender to be joined as an additional party in any proceeding for such purpose.

3. Representations and Warranties of the Company and the Guarantor . In connection with the transactions provided for herein, each of the Company and Guarantor hereby represents and warrants to the Lenders that:

3.1 Corporate Existence . Such Note Party (i) is duly organized, validly existing and in good standing under the laws of the State of Delaware, (ii) has all requisite power and authority to own and operate its properties, to carry on its business as now conducted and as proposed to be conducted, to enter into this Agreement and the other Note Documents to which such Note Party is a party and to carry out the transactions contemplated thereby, and (iii) is qualified to do business and in good standing in every jurisdiction where its assets are located and wherever necessary to carry out its business and operations, except in jurisdictions where the failure to be so qualified or in good standing has not had, and could not be reasonably expected to have, a Material Adverse Effect.

3.2 Authorization . All corporate action has been taken on the part of each Note Party and each of their respective managers, members, officers, directors and stockholders necessary for the authorization, execution and delivery of this Agreement and the Notes. The issuance of the Notes will not be subject to the preemptive rights of any stockholder of the Company or member of the Guarantor that has not already been waived.

3.3 Compliance with Other Instruments . Neither the authorization, execution and delivery of this Agreement, nor the issuance and delivery of the Notes, will constitute or result in a material default or violation of any material term or provision of the Company’s current Amended and Restated Certificate of Incorporation, as amended or bylaws or the Guarantor’s Amended and Restated Limited Liability Company Agreement, as amended, or any material agreement or instrument by which the Company or the Guarantor is bound or to which its properties or assets are subject.

3.4 No Government Action . The execution, delivery and performance by such Note Party of this Agreement and the other Note Documents to which such Note Party is a party and the consummation of the transactions contemplated by this Agreement do not and will

5

not require any registration with, consent or approval of, or notice to, or other action to, with or by, any Governmental Authority except (i) for filings and recordings with respect to the Collateral to be made, or otherwise delivered to Lenders for filing and/or recordation and (ii) any registration, consent, approval, notice or action to the extent that the failure to undertake or obtain such registration, consent, approval, notice or action could not reasonably be expected to have a Material Adverse Effect.

3.5 Valid and Binding . This Agreement and the other Note Documents to which such Note Party is a party have been duly executed and delivered by such Note Party and are the legally valid and binding obligations of such Note Party, enforceable against such Note Party in accordance with their respective terms, except as may be limited by bankruptcy, insolvency, reorganization, moratorium or similar laws relating to or limiting creditors’ rights generally or by equitable principles relating to enforceability.

3.6 No Material Adverse Effect . Since March 31, 2007, no event, circumstance or change has occurred that has caused or evidences, either in any case or in the aggregate, a Material Adverse Effect.

3.7 Compliance with Law . Each of such Note Party is in compliance with all applicable statutes, regulations and orders of, and all applicable restrictions imposed by, all Governmental Authorities, in respect of the conduct of its business and the ownership of its property, except such non-compliance that, individually or in the aggregate, could not reasonably be expected to result in a Material Adverse Effect.

4. Representations and Warranties of the Lenders . In connection with the transactions provided for herein, each Lender hereby represents and warrants to the Note Parties that:

4.1 Authorization . This Agreement constitutes such Lender’s valid and legally binding obligation, enforceable in accordance with its terms, except as may be limited by (i) applicable bankruptcy, insolvency, reorganization, or similar laws relating to or affecting the enforcement of creditors’ rights and (ii) laws relating to the availability of specific performance, injunctive relief or other equitable remedies. Each Lender represents that it has full corporate power and authority to enter into this Agreement.

4.2 Purchase Entirely for Own Account . Each Lender acknowledges that this Agreement is made with Lender in reliance upon such Lender’s representation to the Note Parties that the Notes will be acquired for investment for Lender’s own account, not as a nominee or agent, and not with a view to the resale or distribution of any part thereof, and that such Lender has no present intention of selling, granting any participation in, or otherwise distributing the same. By executing this Agreement, each Lender further represents that such Lender does not have any contract, undertaking, agreement or arrangement with any person to sell, transfer or grant participations to such person or to any third person, with respect to the Notes.

4.3 Disclosure of Information . Each Lender acknowledges that it has received all the information it considers necessary or appropriate for deciding whether to acquire

6

the Notes. Each Lender further represents that it has had an opportunity to ask questions and receive answers from the Note Parties regarding the terms and conditions of the offering of the Notes.

4.4 Investment Experience . Each Lender is an investor in securities of companies in the development stage and acknowledges that it is able to fend for itself, can bear the economic risk of its investment and has such knowledge and experience in financial or business matters that it is capable of evaluating the merits and risks of the investment in the Notes. If other than an individual, each Lender also represents it has not been organized solely for the purpose of acquiring the Notes.

4.5 Accredited Investor . Each Lender is an “accredited investor” within the meaning of Rule 501 of Regulation D of the Securities and Exchange Commission (the “SEC” ), as presently in effect.

4.6 Restricted Securities . Each Lender understands that the Notes are characterized as “restricted securities” under the federal securities laws inasmuch as they are being acquired from the Company in a transaction not involving a public offering and that under such laws and applicable regulations such securities may be resold without registration under the Act only in certain limited circumstances. Each Lender represents that it is familiar with SEC Rule 144, as presently in effect, and understands the resale limitations imposed thereby and by the Act.

4.7 Further Limitations on Disposition . Without in any way limiting the representations and warranties set forth above, each Lender further agrees not to make any disposition of all or any portion of the Notes unless and until such Lender has received the prior written consent of the other Lender and the transferee has agreed in writing for the benefit of the Company to be bound by this Section 4 and:

(a) There is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in accordance with such registration statement; or

(b) (i) Lender has notified the Company of the proposed disposition and has furnished the Company with a detailed statement of the circumstances surrounding the proposed disposition and (ii) if reasonably requested by the Company, Lender shall have furnished the Company with an opinion of counsel, reasonably satisfactory to the Company that such disposition will not require registration of such shares under the Act. It is agreed that the Company will not require opinions of counsel for transactions made pursuant to Rule 144 except in extraordinary circumstances.

4.8 Legends . It is understood that the Notes may bear the following legend:

“THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. IT MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED, HYPOTHECATED, OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR AN OPINION

7

OF COUNSEL SATISFACTORY TO THE COMPANY THAT REGISTRATION IS NOT REQUIRED UNDER SUCH ACT OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SUCH ACT.”

5. State Commissioners of Corporations . THE SALE OF THE SECURITIES WHICH ARE THE SUBJECT OF THIS AGREEMENT HAS NOT BEEN QUALIFIED WITH THE COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA AND THE ISSUANCE OF SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION FOR SUCH SECURITIES PRIOR TO SUCH QUALIFICATION IS UNLAWFUL, UNLESS THE SALE OF SECURITIES IS EXEMPT FROM QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THIS AGREEMENT ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION BEING OBTAINED, UNLESS THE SALE IS SO EXEMPT.

6. Covenants and Agreements . Each Note Party hereby covenants and agrees that:

6.1 Corporate Existence . Each Note Party will at all times preserve and keep in full force and effect its existence and all rights and franchises, licenses and permits material to its business; provided, neither any such Note Party (other than the Company with respect to existence) shall be required to preserve any such existence, right or franchise, licenses and permits if an executive officer of such Note Party shall determine that the preservation thereof is no longer desirable in the conduct of the business of such Person, and that the loss thereof is not disadvantageous in any material respect to such Person or to Lenders.

6.2 Compliance with Law . Such Note Party will comply with the requirements of all applicable laws, rules, regulations and orders of any Governmental Authority (including those relating to environmental matters), noncompliance with which could reasonably be expected to have, individually or in the aggregate, a Material Adverse Effect.

6.3 Liens on Collateral . Except for the security interest created by this Agreement, such Note Party shall not create or suffer to exist any Lien upon or with respect to the Collateral, and the Company shall defend the Collateral against all Persons at any time claiming any other interest therein.

6.4 Rights in Collateral . Such Note Party shall not take or permit any action which could materially impair Lenders’ rights in the Collateral except as otherwise permitted under this Agreement.

6.5 Other Information . Such Note Party shall provide any information reasonably requested by Lenders with respect to the Collateral.

7. Conditions to Purchase .

7.1 Conditions to Each Purchase . The obligation of Lenders to purchase any Note on any Purchase Date is subject to the satisfaction or waiver of the following conditions precedent:

(a) Purchase Notice . Lenders shall have received a fully executed and delivered Purchase Notice, together with evidence, in form and substance reasonably satisfactory to the Lenders, of the approval of such Purchase Notice by the Board of Directors of the Company, including the approval of the Class B Directors of the Company as contemplated by Section 7.1(c) below.

8

(b) Note Documents . Lenders shall have received a copy of each Note Document originally executed and delivered by each applicable Note Party, including an original of a fully executed Note in the principal face amount of such Lender’s Commitment.

(c) Class B Directors Approval . Each Purchase Notice shall be unanimously approved by the Class B Directors of the Company. Class B Directors shall have the meaning ascribed to such term in the Amended and Restated Certificate of Incorporation of HELIO, Inc.

(d) Helio Note . The Company shall have endorsed the Helio Note to the Lenders as security for the Obligations on terms and conditions satisfactory to the Lenders.

(e) Amount . After purchasing the Notes on such Purchase Date, the aggregate principal amount of all outstanding Notes shall not exceed the Maximum Note Amount.

(f) Outstanding Note Schedule . On each Purchase Date, the Outstanding Note Schedule attached hereto as Exhibit A shall be amended to reflect the aggregate principal amount of all Notes outstanding as of such Purchase Date.

(g) No Default . As of such Purchase Date, no event shall have occurred and be continuing or would result from the purchase of the Notes that would constitute an Event of Default or a Default.

(h) Representations and Warranties . The representations and warranties of the Company and the Guarantor contained in Section 3 hereof shall be true and correct in all material respects on and as of such Purchase Date, except to the extent that such representations and warranties specifically refer to an earlier date, in which case they are true and correct in all material respects as of such earlier date.

(i) Other Documents . Lenders shall have received such other documents as Lenders may reasonably request.

8. Grant of Security .

8.1 Grant of Security . The Company hereby grants to Lenders a security interest in and continuing lien on all of the Company’s right, title and interest in, to and under the HELIO Loan, including all outstanding and unpaid principal and interest relating thereto, whether now owed or existing or hereafter acquired or arising (all of which being hereinafter collectively referred to as the “ Collateral ”).

9

8.2 Security for Obligations . This Agreement secures, and the Collateral is collateral security for, the prompt and complete payment or performance in full when due, whether at stated maturity, by required prepayme