I've blogged on a number of occasions about distributed computing, which allows you to contribute your unused computing power to advance scientific research, because I think that's the single biggest thing most of us can do right now to improve the state of science and technology.
But now you can do even more. The Folding@Home project at Stanford University has new client software for their protein folding simulation that will allow it to run on a Sony PlayStation 3.
According to the Folding@Home website, with about 10,000 PS3s online, the researchers would be able to achieve performance on the petaflop scale. With software from Sony, the PlayStation 3 will now be able to contribute to the Folding@Home project, pushing Folding@Home a major step forward.