SETI@home

SETI (Search for Extraterrestrial Intelligence) is a scientific area whose goal is to detect intelligent life outside Earth. One approach, known as radio SETI, uses radio telescopes to listen for narrow-bandwidth radio signals from space. Such signals are not known to occur naturally, so a detection would provide evidence of extraterrestrial technology.

SETI Home

Download, install and run the BOINC software used by SETI@home.
When prompted, enter the URL: http://setiathome.berkeley.edu