A few months ago, Radiohead released the individual instrument tracks for "Nude" and invited folks to remix it. Now they have done the same for "Reckoner."
The whole thing is designed for Garage Band (and funneled through iTunes), but with a little computer magic, you can do a remix on your PC too.
The widget for one of mine is above. It focuses more on Yorke's voice, and dirties-up the guitar parts.