Do you fold at home?
Distributed computing is spreading a large computing task over multiple computers. In the case of Folding@Home, it's installing a program on your computer that uses your computers leftover computer power to fold protein in the background. Most of the time your computer isn't being used to 100% of its capacity so you probably have power to spare. In this case it's for a good cause as the data is used, among other things, to help fight disease.
Most of the time I don't even notice the program is running. When I'm going to do something "intensive" like... um... play Warcraft III, I turn it off.
If you do decide to give Folding@Home a try, please consider joining our team.