I've been meaning to try Linux on my PS3, but haven't gotten around to it yet. I definitely will one of these days, so will let you know how it goes. I've never tried any Linux OS before though, so I'll probably be messing about quite a lot to start with.

Yes, the PS3s ability to install a second OS is definitely intentional on Sony's part. The option is right there in the system menu; "Install Other OS".