Folding@home is a feature under Network on the PS3 Home Menu. It is a distributed computing project that is run by Stanford University. The goal of the project is to research protein folding mechanisms in the hope that this will lead to medical treatments for related diseases. You can help out by allowing Stanford University to use your PS3 when is it idle. The power of the PS3 means you contribute a significant amount of CPU time to the project. More information can be found at http://folding.stanford.edu/.