Since many of you have more than one pc, why not use it for cancer/AIDS research with a simple program that you can set up so it only runs when pcs is idle?
"Grid.org is a single destination site for large-scale, non-profit research projects of global significance. With the participation of over 3 million devices worldwide, grid.org projects like Cancer Research, Anthrax Research, Smallpox Research and the new Human Proteome Folding Project (running in conjunction with IBM's new World Community Grid) have achieved record levels of processing speed and success."
More info
http://www.grid.org
To download
http://www.grid.org/download/gold/download.htm
Do a good thing
