You're lucky I remember it was on one of the Now CD's, and since I'm home sick this weekend, I happen to have a stack of my old CD cases within arm's reach. I believe the song you're looking for is called "Everybody's Free (to Wear Sunscreen)" by Baz Luhrmann.
ETA: It was the class of '99!
http://www.youtube.com/watch?v=sTJ7AzBIJoI