"More than one million PlayStation 3 owners are taking part in Folding@home, the distributed computing project run by Stanford University." The research helps finding cure for Alzheimer's, Mad Cow (BSE), CJD, ALS, Huntington's, Parkinson's disease, and many cancers.
The distributed computing application runs on many platforms, including the newest game console from Sony. Wired says "PS3s currently comprise about 74 percent of the entire computing power of Folding@home." The instructions on how to download the required software are on the Playstation blog.