Visible crew/equipment: When Tom Cruise is standing alone in the hall at the ground floor of the LE building, screaming for "Tech Support..." the camera pans around him 360 degrees. When the camera pans over Tom's left shoulder, you can see the shadows of the camera crew on his jacket. After the panning has come to a stop, you can see the reflection of two or three crew-members in the glass walls behind him.
Visible crew/equipment: When the camera zooms in on David's car after he's nearly crashed, you can see the camera to the right of the reflection in the window.
Visible crew/equipment: When David is about to leave for L.E. there is a very brief shot of him in the back of a car looking out with his mask on. Just above the door handle you can see the dark reflection of the camera.
Answer: It's from an Icelandic band called "Sigur Ros", and it is not on the soundtrack (although another one of their songs is - one from earlier in the movie). It's from their 2002 album titled "()" - yes two parenthesis, it's on track 4, but is an untitled song. You can get the album on Amazon.com or in any Borders or Barnes and Noble.