Photos: Getting your green on for Earth Day

Green your ride. The price of oil has plummeted from almost $150 a barrel last year to around $50 this year, cutting gasoline prices way below the $4 per gallon Americans were paying last year. With lower prices, it seems people are going back to buying gas guzzlers, no doubt helped by the generous terms dealers are offering. But few industry analysts think that gasoline prices will stay where they are indefinitely--all the more reason to seek out fuel-efficient cars.

The next big technology change in cars is electric vehicles, which studies have shown are less polluting than all-gasoline engines, particularly if cars are charged at night. In the next two years, a number of cars will be coming out from the big incumbents to start-ups that will offer a big leap in efficiency. Depending on your driving habits, you may never need to go to gas stations.

Of course, the best way to green your ride is to leave your car at home and use an alternate mode of transportation, such as biking or mass transit.

See CNET Car Tech's green and hybrid car buying guide.