Google as a jukebox:
1. bookmark this search http://www.google.com/search?q=site%3Amuxtape.com
2. choose randomly one result
3. click on a track (quite easy)
4. let it play

There are currently 61 muxtapes, i.e around 171 tracks. Free. Legal – but only on the listener side.

Better search:
http://www.google.com/search?q=site%3Amuxtape.com+-%22a+simple+way%22