Buy a bicycle (if you dont already have one) and ride it for those little trips to the store or to rent a movie, etc.
Or walk... helps with them 6 pack abs too...

Fight for the greenbelt / undeveloped land in your area, dont let it get sold out and turned into condos.
use organic products for things like weed killing. They also have environmentally safe parts cleaning solutions (solvent) for those of you that are into fixing cars / bikes etc.
Go to a car wash that recycles their water, uses less water and doesn't wash soap and chemicals into the sewer.
Conserve energy by wearing some clothes or grabbing a blanket instead of turning the heat up. Buy a kiddie pool and flop around in it in the summer when its hot and keep the AC usage down.
Chill on the wood fires, once in awhile is ok but for a main source of heat look into a pellet stove or something a little more efficient and less polluting.
those are the things we try to do (along with your typical recycling and such).