I read the tip of the week from Global Green News that said Driving 15 miles less a week eliminates up to  900 lbs of CO2 per year.

If 15 miles less a week can do this just think about 30 to 60 miles less a week.  Stop and think before you jump into the car to go somewhere you really do not need to go but you are just bored.  How about doing all your errands at one time instead of driving to town 10 times for items your forgot to pick up.  How about carpooling.  We carpool to work how about carpooling to shop with your friends.

Make a list of things you need to do and map it out.  Go out and buy a bike even if it has 3 wheels or try walking.  Just think of the health bonus that would come from biking or walking as you come a slimmer you.