http://www.seti.org/site/pp.asp?c=ktJ2J9MMIsE&b=179086
thats the seti at home. basicaly it analizyes all the data from the radio antenas their using on your computer by using your prosesing space while your not using it. it dosnt use your computer when your computers not on its screensaver. its pretty cool though you can look at all the radio waves coming through.