EXHIBIT A JOINT FILING AGREEMENT

EXHIBIT A

JOINT FILING AGREEMENT

     In accordance with Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them a Statement on Schedule 13G (including amendments thereto) with regard to the Common Stock of InPhonic, Inc., and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In evidence thereof, the undersigned, being duly authorized, hereby execute this Joint Filing Agreement as of May 7, 2007.

		MSD CAPITAL, L.P.
		By:		MSD Capital Management LLC, its general partner
				By:		/s/ Xxxx X. Xxxxxx Xxxx X. Xxxxxx
						Manager and General Counsel
		PT INVESTMENTS I, L.P.
		By:		MSD Capital, L.P., its general partner
		By:		MSD Capital Management LLC, its general partner
				By:		/s/ Xxxx X. Xxxxxx Xxxx X. Xxxxxx
						Manager and General Counsel