What is the song on the latest CSI commercial?

Answer 1

IF you are talking about the commercial's that have been playing in late March 2008 the answer is "Are you with me" by Vaux if not im not sure.

If you are referring to the commercial for the episode after Warrick gets shot, the song is "The Funeral" by Band of Horses.
Check it out on YouTube, the part from the commercial is a little bit into the song.

If you are talking about the one playing as of 9/20/09, its sang by Visual Audio Sensory Theater (V.A.S.T.) and the song is called "Touched".