I remember reading on the listservs a while back about all the crazy demands some celebrities put in their contract riders (ah hem, Mary J. Blige, do you really need a new toilet seat installed just for your use?). Then today on BoingBoing I saw that there actually was a reason why Van Halen demanded a bowl of M&Ms with all the brown ones removed. Here's the rationale, from Snopes.
The prize for the most interesting contract, though, must go to the Foo Fighters. Here's a copy, courtesy of The Smoking Gun (warning: There's some language that some could find offensive).