Or... you can search for ET with SETI@Home. Two versions are up and running. The classic version
http://seticlassic.ssl.berkeley.edu or the BOINC version
http://setiathome.berkeley.edu
If you use the BOINC, you can run multiple projects at the same time:
# Climateprediction.net: study climate change
# Einstein@home: search for gravitational signals coming from pulsars
# LHC@home: improve the design of the CERN LHC particle accelerator
# Predictor@home: investigate protein-related diseases
# SETI@home: Look for radio evidence of extraterrestrial life