I've decided that I want to set up a few spare PCs to run Folding @ Home. It would be better if I didn't consume any Windows licenses doing so, and they really don't have to do much else. The "which distro" question probably isn't too hard these days, but I haven't been following what's been going on much with Linux. Ideally I want something that comes in both 32 bit and 64 bit versions and can be run headlessly without too much difficulty. The easier to install, the better - I don't want to waste too much time with this, so I don't care if I end up with a Fisher-Price version.
Sorry if the question seems vague or ridiculous, I just don't know much about Linux anymore. Last time I seriously played with it 2.6.x was still cutting edge.