OK, anyone with spare CPU cycles (and who doesn't have a few of THOSE lying around) - UD.com (United Devices) is distributing a SETI-like app/screensaver that will use idle CPU cycles to help find a cure for cancer and do genetic research.
Not only are you helping your fellow man, but they enter you in drawings for some prizes, like a trip to Boston to see the Blue Man Group, free plane tickets, PS2's and cash.
If you're interested, I have created a GotApex team that you can join. Not a lot of people are running this app yet, so we have a good shot at going to the top of the list - http://members.ud.com/services/teams/
To join, go to http://www.ud.com/home.htm and click on 'Volunteer your PC'.