Extraterrestrial Life

The Planetary Society
A nonprofit organization devoted to the exploration of the solar system and the search for extraterrestrial life.
http://www.planetary.org/

The Rise and Fall of Star Faring Civilizations in Our Own Galaxy
Speculation, based on the Drake Equation, regarding the existence and composition of alien civilizations.
http://www.jrmooneyham.com/ctcta.html

Search for ET!
Interactive Flash tutorial exploring the possibility of and search for life on other worlds.
http://jvsc.jst.go.jp/universe/et_e/index_e.htm