Nice find, had I a PS3, I'd be already doing some hello world graphics thing and signing it to run lol.
Perhaps a LAMP server running could be a good idea? With a hash bruteforcer running off the GPU in a thread pool. Reminds me the day a CA cert was bruteforced with 200 PS3s.
Bitcoin... if you know what I mean.
EDIT: https://github.com/verement/cellminer
Who would have thought...