“Look again at that dot. That’s here. That’s home, That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ’superstar,’ every ’supreme leader,’ every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.
Carl Sagan from ‘Pale Blue Dot’

Some other Sagan links:
http://www.coseti.org/klaescnt.htm - a lot of information about the movie ‘Contact’

http://www.sciencenter.org/SaganPW/ - A planet walk dedicated to Carl Sagan with numbers given for a scaled down version of the solar system.

http://paleblue.us/about.html - another blog inspired by ‘pale blue dot’