http://news.bbc.co.uk/2/hi/technology/7443557.stm
"A supercomputer built with components designed for the Sony PlayStation 3 has set a new computing milestone.
The IBM machine, codenamed Roadrunner, has been shown to run at "petaflop speeds", the equivalent of one thousand trillion calculations per second.
The benchmark means the computer is twice as nimble as the current world's fastest machine, also built by IBM."
I have to say that this is pretty impressive - not using Cell processors solely though but still shows what the processor is capable of doing for certain applications.