I've written a plugin for Winamp that allows users to stream Grateful Dead shows from archive.org's enormous collection of user-uploaded audience and soundboard recordings.
It randomly chooses a show, streams it, and when it's done, randomly chooses another. I wrote this for myself to listen to the Dead at work, but I figured I'd spread the joy.
If you have the latest version of Winamp, you can download my plugin here.
If you don't have the latest version of Winamp, you can download it free here.