Exhibit
      10.2

     

    FORM
      OF WARRANT PURCHASE AGREEMENT

    


    THIS
      WARRANT PURCHASE AGREEMENT (this “Agreement”)
      entered into as of the 11th
      day of
      October, 2007, by and between SRKP 21, Inc., a Delaware corporation with an
      address at 4737 North Ocean Drive, Suite 207, Lauderdale by the Sea, FL 33308
      (the “Company”)
      and
      [Name of Investor], an individual with an address at [Address of Investor]
      (the
“Purchaser”).

    


    WHEREAS,
      the Purchaser desires to purchase, and the Company desires to sell, a warrant
      in
      the form attached hereto as Exhibit
      A
      (the
“Warrant”)
      to
      purchase [Number of Shares] shares (the “Shares”)
      of the
      Company’s common stock, par value $.0001 per share (the “Common
      Stock”),
      upon
      the terms and conditions hereof.

    


    NOW,
      THEREFORE, in consideration of the premises and the mutual agreements herein
      contained, the Purchaser and the Company hereby agree as follows:

    


    SECTION
      1: SALE OF THE WARRANT

    


    1.1
      Sale
      of the Warrant.
      Subject
      to the terms and conditions hereof, the Company will sell and deliver to the
      Purchaser and the Purchaser will purchase from the Company, upon the execution
      and delivery hereof, the Warrant for a purchase price equal to [Aggregate
      Purchase Price] (the “Purchase
      Price”).
      

     

    SECTION
      2: CLOSING DATE; DELIVERY

    


    2.1
      Closing
      Date.
      The
      closing of the purchase and sale of the Warrant hereunder (the “Closing”)
      shall
      be held immediately following the execution and delivery of this
      Agreement.

    


    2.2
      Delivery
      at Closing.
      At the
      Closing, the Company will deliver to the Purchaser the Warrant in the
      Purchaser’s name, representing the right to purchase the Shares to be purchased
      by Purchaser hereunder, against payment of the Purchase Price. 

    


    SECTION
      3: REPRESENTATIONS AND WARRANTIES OF PURCHASER

    


    The
      undersigned Purchaser hereby represents and warrants to the Company as
      follows:

     

    3.1
      Transfer
      Restrictions.
      Neither
      the Warrant, nor, upon issuance, the Shares, has been registered under the
      Securities Act of 1933, as amended (the “Securities
      Act”)
      and
      cannot be sold or otherwise transferred without an effective registration or
      an
      exemption therefrom, but may not be sold pursuant to the exemptions provided
      by
      Section 4(1) of the Securities Act or Rule 144 under the Securities Act, in
      accordance with the letter from Richard K. Wulff, Chief
      of
      the Office of Small Business Policy of the Securities and Exchange Commission’s
      Division of Corporation Finance,
      to Ken
      Worm of NASD Regulation, Inc., dated January 21, 2000.

    


    3.2
      Experience.
      The
      undersigned has such knowledge and experience in financial and business matters
      that the undersigned is capable of evaluating the merits and risks of investment
      in the Company and of making an informed investment decision. The undersigned
      has adequate means of providing for the undersigned's current needs and possible
      future contingencies and the undersigned has no need, and anticipates no need
      in
      the foreseeable future, to sell the Warrant for which the undersigned subscribes
      or, upon issuance, the Shares. The undersigned is able to bear the economic
      risks of this investment and, consequently, without limiting the generality
      of
      the foregoing, the undersigned is able to hold the Warrant or, upon issuance,
      the Shares, for an indefinite period of time and has sufficient net worth to
      sustain a loss of the undersigned's entire investment in the Company in the
      event such loss should occur. Except as otherwise indicated herein, the
      undersigned is the sole party in interest as to its investment in the Company,
      and it is acquiring the Warrant solely for investment for the undersigned’s own
      account and has no present agreement, understanding or arrangement to subdivide,
      sell, assign, transfer or otherwise dispose of all or any part of the Warrant
      subscribed for or, upon issuance, the Shares, to any other person.



    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    3.3
      Investment;
      Access to Data.
      The
      undersigned has carefully reviewed and understands the risks of, and other
      considerations relating to, a purchase of the Warrant and the underlying Shares
      and an investment in the Company. The undersigned has been furnished materials
      relating to the Company, the private placement of the Warrants or anything
      else
      that it has requested and has been afforded the opportunity to ask questions
      and
      receive answers concerning the terms and conditions of the offering and obtain
      any additional information which the Company possesses or can acquire without
      unreasonable effort or expense. Representatives of the Company have answered
      all
      inquiries that the undersigned has made of them concerning the Company, or
      any
      other matters relating to the formation and operation of the Company and the
      offering and sale of the Warrants. The
      undersigned has not been furnished any offering literature other than the
      materials that the Company may have provided at the request of the undersigned;
      and the undersigned has relied only on such information furnished or made
      available to the undersigned by the Company as described in this Section. The
      undersigned is acquiring the Warrant for investment for the undersigned's own
      account, not as a nominee or agent and not with the view to, or for resale
      in
      connection with, any distribution thereof. The undersigned acknowledges that
      the
      Company is a start-up company with no current operations, assets or operating
      history, which may possibly cause a loss of Purchaser’s entire investment in the
      Company. 

    


    3.4
      Authorization.
      (a)
      This Agreement, upon execution and delivery thereof, will be a valid and binding
      obligation of Purchaser, enforceable in accordance with its terms, subject
      to
      applicable bankruptcy, insolvency, reorganization and moratorium laws and other
      laws of general application affecting enforcement of creditors' rights
      generally.

    


    (b)
      The
      execution, delivery and performance by Purchaser of this Agreement and
      compliance therewith and the purchase and sale of the Warrant will not result
      in
      a violation of and will not conflict with, or result in a breach of, any of
      the
      terms of, or constitute a default under, any provision of state or Federal
      law
      to which Purchaser is subject, or any mortgage, indenture, agreement,
      instrument, judgment, decree, order, rule or regulation or other restriction
      to
      which the Purchaser is a party or by which the undersigned Purchaser is bound,
      or result in the creation of any mortgage, pledge, lien, encumbrance or charge
      upon any of the properties or assets of Purchaser pursuant to any such
      term.

    


    3.5
      Accredited
      Investor.
      Purchaser is an accredited investor as defined in Rule 501(a) of Regulation
      D
      under the Securities Act of 1933, as amended.

    


    SECTION
      4: MISCELLANEOUS

    


    4.1
      Governing
      Law.
      This
      Agreement shall be governed in all respects by the laws of the State of
      Delaware, without regard to conflicts of laws principles thereof.

    


    4.2
      Survival.
      The
      terms, conditions and agreements made herein shall survive the Closing.


    


    4.3
      Successors
      and Assigns.
      Except
      as otherwise expressly provided herein, the provisions hereof shall inure to
      the
      benefit of, and be binding upon, the successors, assigns, heirs, executors
      and
      administrators of the parties hereto.

    


    4.4
      Entire
      Agreement; Amendment; Waiver.
      This
      Agreement constitutes the entire and full understanding and agreement between
      the parties with regard to the subject matter hereof. Neither this Agreement
      nor
      any term hereof may be amended, waived, discharged or terminated, except by
      a
      written instrument signed by all the parties hereto.

    



    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    4.5
      Counterparts.
      This
      Agreement may be executed in any number of counterparts, each of which shall
      be
      an original, but all of which together, shall constitute one
      instrument.


    


    IN
      WITNESS WHEREOF,
      the
      undersigned have hereunto set their hands as of the day and year first above
      written.

    


    
      	
              SRKP
                21, INC.

            
	 
	
              By:

            	
              /s/
                Richard A. Rappaport

            
	
              Name:

            	
              Richard
                A. Rappaport

            
	
              Title:

            	
              President

            
	 	 
	
                  /s/
                Name of Investor

            
	
              [Name
                of Investor]

            


    


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    Exhibit
      A

    


    (See
      Exhibit 4.1 to this registration statement for form of warrant)