Exhibit 99.8

Joint Filing Agreement

The undersigned hereby agrees that they are filing jointly pursuant to Rule 13d-1(k)(1) of the Securities Exchange Act of 1934, as amended, with respect to the shares of common stock of Virgin Mobile USA, Inc. The undersigned further agree and acknowledge that such shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning it contained herein, but shall not be responsible for completeness and accuracy of the information concerning the other, except to the extent that it knows or has reason to believe that such information is inaccurate.

Dated: September 11, 2008	Corvina Holdings Limited
	By:	/s/    Frank Dearie
	Name:	Frank Dearie
	Title:	Director
	Cortaire Limited
	By:	/s/    Frank Dearie
	Name:	Frank Dearie
	Title:	Director
	Gamay Holdings Limited
	By:	/s/    Frank Dearie
	Name:	Frank Dearie
	Title:	Director
	Virgin Group Holdings Limited
	By:	/s/    Frank Dearie
	Name:	Frank Dearie
	Title:	Director
	/s/    Sir Richard Branson
	Sir Richard Branson
	Cougar Investments Limited
	By:	/s/    Alison Jane Renouf
	Name:	Alison Jane Renouf
	Title:	Director
	Plough Investments Limited
	By:	/s/    Alison Jane Renouf
	Name:	Alison Jane Renouf
	Title:	Director
	Deutsche Bank Trustee Services (Guernsey) Limited
	By:	/s/    Alison Jane Renouf /s/    Tracy Ann Martel
	Name:	Alison Jane Renouf
		Tracy Ann Martel
	Title:	Authorized Signatories
	RBC Trustees (CI) Limited
	By:	/s/    Frank Dearie
	Name:	Frank Dearie
	Title:	Authorized Signatory