In a somewhat similar vein, the Sierra Club reminds us that just riding a bike doesn't automatically make you a green warrior. Take their quiz and see how you rate.
As you can see at right, I did okay, but the Sierrans make it clear I've got room to improve.
I'll give you a big, fat hint for getting maximum points on one of the questions, but you didn't hear this from me:
(Bambucicletta image via the American Bamboo Society.)