There is a free Linux distribution based on Debian for use on the PS3. This distribution "Debian Live for PS3" is available on a bootable CD.
It's great to see Linux working on consoles legally. It is good to have Linux working on more platforms, but also the console makers acknowledging the hackers and trying to harness their energy. Admittedly it is limited by not allowing complete hardware access but at least it is a step forward from the previous generation of consoles.