For a while now, I've been letting the 'unused' clock cycles on my PC's be used for SETI@home - a distributed computing project based around SETI (Search for Extraterrestrial Intellegence). I recently found a group (at SETI@home) called Space Empires and have contributed my 'results' to that group.
I suspect that many people that visit this board may have an interest in SETI and would like to participate. If you're interested, read about it at:
http://setiathome.berkeley.edu/
The software (downloadable from that site)that does this is pretty cool and you may be the lucky one to find a SETI signal and get your name recorded in the history books! I thought it was pretty cool that I could do my small part in this search. If you decide to do it, consider putting your results into the Space Empires group...