I've got Gentoo linux running on my PS3
there's a few things that are annoying though - linux doesn't actually have access to the RSX chip - all the graphics are done in framebuffer mode.
There's also no wifi and I think there's something about the way Sony have done the bluetooth stuff so the remote isn't working yet (apparently some people think they have a way)
I use it for playing all my XVids through my PS3 - and might install Quake3 sometime