What a cool idea. Trent Reznor put NINs new single in Garage Band format, so you can download the tracks and do your own mix.
NIN Hand That Feeds

You need a Mac and Garage Band (free with most newer Macs) to do it, but I love this idea. I'm sure the labels will be pissed he's essentially giving the song away.

Mogwai did a similar thing last year with their song "Hunted by a Freak", but that was for Cubase and you couldn't download it, it just came as a file on the CD.

Beck did it a few years ago through a site called tonos.
they had a competition for the 'best' remix.and then beck performed the winners version at some show on the east coast.
it's pretty cool,more bands should do it.

I think this is a swell idea. Anytime you can give people the ability to bring out what they feel in music it gets my approval. That doesn't count for much, but whatever.

i think the beastie boys did it years ago as well

I think more bands should have independent labels