I'm sure you guys have heard all the blahblah about earth hour and stuff. Here's something else, something really easy to do:
earthlab.com
They calculate your carbon output (mine's 6 tons/year o_o!!!) and offer a huge list of things you can do to lower it. Stupid stuff like remembering that the caps on recyclable bottles aren't recyclable themselves and using cold water to wash your clothes and putting a plastic bottle filled with water or stones or something in your toilet tank and stuff. All sorts of tiny tiny things that take almost no effort to do, but seriously help save resources.