I don't remember who brought this idea up a couple of months ago, but I ran across this article about leveraging home PCs.
Grid Computing Project Article

A small excerpt from the article:
Volunteers will be asked to download a program to their computers that runs when the machine is idle and reaches out to request data to contribute to research projects.

Organizers say the Grid can help unlock genetic codes that underlie diseases like AIDS (news - web sites) and HIV (news - web sites), Alzheimer's or cancer, improve forecasting of natural disasters and aid studies to protect the world's food and water supply.

The massive volunteer project will be unveiled Tuesday by Sam Palmisano, CEO of International Business Machines Corp. (IBM), the world's largest computer company, along with United Nations (news - web sites) officials, researchers from the Mayo Clinic, Oxford University and South Africa, and others.