Lightspace Corporation Warrant Certificate to Purchase Common Stock (with Continental Stock Transfer & Trust Company as Warrant Agent)

Exhibit 4.2

WARRANT CERTIFICATE TO
PURCHASE ONE SHARE OF COMMON STOCK

LIGHTSPACE CORPORATION

                                    CUSIP         

THIS CERTIFIES THAT, FOR VALUE RECEIVED

or registered assigns (the "Registered Holder") is the owner of the number of Warrants (the "Warrants") specified above. Each Warrant initially entitles the Registered Holder to purchase, subject to the terms and conditions set forth in this Certificate and the Warrant Agreement (as hereinafter defined), one fully paid and nonassessable share of Common Stock, $.00001 par value, of Lightspace Corporation, a Delaware corporation (the "Company"), at any time between [                        ], 2006 (the "Initial Warrant Exercise Date"), and the Expiration Date (as hereinafter defined) upon the presentation and surrender of this Warrant Certificate with the Subscription Form on the reverse hereof duly executed, at the corporate office of Continental Stock Transfer & Trust Company, 17 Battery Place, New York New York 10004, as Warrant Agent, or its successor (the "Warrant Agent"), accompanied by payment of [$1.00 in the case of $1.00 Unit Warrants, $1.25 in the case of the $1.25 Unit Warrants, $1.63 in the case of the $1.63 Unit Warrants, $0.80 in the case of the $0.80 Exchange Warrants, $1.00 in the case of the $1.00 Exchange Warrants, $3.00 in the case of the $3.00 Exchange Warrants and $7.50 in the case of the $7.50 Exchange Warrants] subject to adjustment (the "Purchase Price"), in lawful money of the United States of America in cash or by certified or bank check made payable to the Company.

        This Warrant Certificate and each Warrant represented hereby are issued pursuant to and are subject in all respects to the terms and conditions set forth in the Warrant Agreement (the "Warrant Agreement"), dated [                        ], 2006, by and between the Company and the Warrant Agent.

        In the event of certain contingencies provided for in the Warrant Agreement, the Purchase Price and the number of shares of Common Stock subject to purchase upon the exercise of each Warrant represented hereby are subject to modification or adjustment.

        Each Warrant represented hereby is exercisable at the option of the Registered Holder, but no fractional interests will be issued. In the case of the exercise of less than all of the Warrants represented hereby, the Company shall cancel this Warrant Certificate upon the surrender hereof and shall execute and deliver a new Warrant Certificate or Warrant Certificates of like tenor, which the Warrant Agent shall countersign, for the balance of such Warrants.

        The term "Expiration Date" shall mean 5:00 p.m. (New York time) on [                        ], 2011. If such date shall in the State of New York be a holiday or a day on which the banks are authorized to close, then the Expiration Date shall mean 5:00 p.m. (New York time) the next following day which in the State of New York is not a holiday or a day on which banks are authorized to close.

        The Company shall not be obligated to deliver any securities pursuant to the exercise of this Warrant unless a registration statement under the Securities Act of 1933, as amended (the "Act), with respect to such securities is effective or an exemption thereunder is available. The Company has covenanted and agreed that it will file a registration statement under the Federal securities laws, use its best efforts to cause the same to become effective, use its best efforts to keep such registration statement current, if required under the Act, while any of the Warrants are outstanding, and deliver a

prospectus which complies with Section 10(a)(3) of the Act to the Registered Holder exercising this Warrant. This Warrant shall not be exercisable by a Registered Holder in any state where such exercise would be unlawful.

        This Warrant Certificate is exchangeable, upon the surrender hereof by the Registered Holder at the corporate office of the Warrant Agent, for a new Warrant Certificate or Warrant Certificates of like tenor representing an equal aggregate number of Warrants, each of such new Warrant Certificates to represent such number of Warrants as shall be designated by such Registered Holder at the time of such surrender. Upon due presentment and payment of any tax or other charge imposed in connection therewith or incident thereto, for registration of transfer of this Warrant Certificate at such office, a new Warrant Certificate or Warrant Certificates representing an equal aggregate number of Warrants will be issued to the transferee in exchange therefor, subject to the limitations provided in the Warrant Agreement.

        Prior to the exercise of any Warrant represented hereby, the Registered Holder shall not be entitled to any rights of a stockholder of the Company, including, without limitation, the right to vote or to receive dividends or other distributions, and shall not be entitled to receive any notice of any proceedings of the Company, except as provided in the Warrant Agreement.

        Prior to due presentment for registration of transfer hereof, the Company and the Warrant Agent may deem and treat the Registered Holder as the absolute owner hereof and of each Warrant represented hereby (notwithstanding any notations of ownership or writing hereon made by anyone other than a duly authorized officer of the Company or the Warrant Agent) for all purposes and shall not be affected by any notice to the contrary, except as provided in the Warrant Agreement.

        This Warrant Certificate shall be governed by and construed in accordance with the laws of the State of Delaware without giving effect to conflicts of laws.

        This Warrant Certificate is not valid unless countersigned by the Warrant Agent.

        IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be duly executed, manually or in facsimile by two of its officers "hereunto duly authorized and a facsimile of its corporate seal to be imprinted hereon.

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Dated: [                        ]

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SUBSCRIPTION FORM

To Be Executed by the Registered Holder
in Order to Exercise Warrants

        The undersigned Registered Holder hereby irrevocably elects to exercise Warrants represented by this Warrant Certificate, and to purchase the securities issuable upon the exercise of such Warrants, and requests that certificates for such securities shall be issued in name of

PLEASE INSERT SOCIAL SECURITY
OR OTHER IDENTIFYING NUMBER

(please print or type name and address)

and be delivered to

(please print or type name and address)

and if such number of Warrants shall not be all the Warrants evidenced by this Warrant Certificate, that a new Warrant Certificate for the balance of such Warrants be registered in the name of, and delivered to, the Registered Holder at the address stated below.

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ASSIGNMENT

To Be Executed by the Registered Holder
in Order to Assign Warrants

FOR VALUE RECEIVED,                        , hereby sells, assigns and transfers unto

PLEASE INSERT SOCIAL SECURITY OR
OTHER IDENTIFYING NUMBER

(please print or type name and address)

                        of the Warrants represented by this Warrant Certificate, and hereby irrevocably constitutes and appoints            Attorney to transfer this Warrant Certificate of the Company, with full power of substitution in the premises.

THE SIGNATURE TO THE ASSIGNMENT OR THE SUBSCRIPTION FORM MUST CORRESPOND TO THE NAME AS WR1TTEN UPON THE FACE OF THIS WARRANT CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER AND MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION WITH MEMBERSHIP IN AN APPROVED SIGNATURE MEDALLION PROGRAM PURSUANT TO SEC RULE 17Ad-15.

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