Carbon rally is a fun interactive site that let's you accept challenges to reduce your CO2 emmision. You can make friends, create teams, and save the world, all at the same time!!!!!!! www.carbonrally.com
While this site isn't exactly interactive it tells you how to reduce your CO2 emiision. Plus, it tells you how much you already emmit. Of course, it's a round figure. www.liveneutral.org
