Greener transportation
Hoofing it, bicycling, and taking public transportation are some of the greenest ways to get around.Walkscore calculates how friendly a neighborhood is to get around on foot. Here's a list of regional bicycle associations, which provide maps and tips for cycling safely. Google Transit provides direction for public transportation in 18 states and some cities abroad. Car-sharing services such as Zipcar may be the next best thing, while major rental agencies and taxi fleets are providing more hybrid vehicles. Carpool Connect and Divide the Ride offer ride-sharing tools. Electric bike rental services will be tested in college towns later this year.

Those who can't part with a car and have a cool six figures to spare can line up behind Gov. Arnold Schwarzenneger to buy a Tesla electric sportscar.

For those on a slimmer budget, some tiny, fuel-efficient cars, driven conservatively, can get more bang for the buck than a hybrid. Keeping the pedal off the metal can boost fuel economy by more than 20 percent. GPS units and traffic data on maps from Google, Yahoo, and Ask can help to avoid fuel-wasting traffic jams. Some gearheads go to extremes by "hypermiling" or tricking out their cars to improve aerodynamics. Regular maintenance and oil changes also help, and "green" motor oil is a new product.