The Wired CD of Creative-Commons licensed music by top performers including The Beastie Boys, Chuck D (neither of whom allow sampling from their tracks!), David Byrne and Brazil’s Minister of Culture (now that’s what I call government taking a positive interest in the arts!).
Read all about it:
http://www.wired.com/wired/archive/12.11/sample.html
http://www.wired.com/wired/archive/12.11/beastie.html
Get the tracks legally online via bittorrent and get sampling (unless you’re a Beaties or Public Enemy fan. Ironwhat?):