the mother lode
As mentioned in this Wired article, the SXSW music festival has put 758 full mp3s online from bands performing there next week. They're available as one gigantic 2.6GB file downloadable via bittorrent. Also, if you browse around the schedule, you can download individual tracks.
I'll be at SXSW this year, but only for the interactive portion of the conference; i can't really stick around for the music :(
If you see me there, say hi and maybe i'll have something for you.
If I were going to be there for the music, I would make absolutely sure to check out Murder By Death's set at 1am on wednesday at Sake on 6th. To see why, check out Killbot 2000.