In the near term, expect an increasing number of hybrid models to choose from at your dealer's lot. The plug-in Chevy Volt has arrived, and boasts a 40 mile, gas-free driving range. A plug-in version of the Toyota Prius will be coming within a year or two, too, along with, perhaps, a lithium-ion-powered version of the newest Prius.

Meanwhile, BMW plans to introduce the X6, a mild hybrid that uses an electric assist motor in both city and highway driving. Mercedes is now leasing a limited number of their ML 450 Hybrid. This SUV uses the same hybrid technology in the X6 developed by BMW, Chrysler, and GM. Expect them for sale once Mercedes-Benz gets their hands on more of the top-of-the-line liquid-cooled high-voltage nickel-metal hydride batteries that the M-series SUVs use.

Unlike Japanese makers like Toyota and Honda, Mercedes-Benz is using hybrid technology to improve the mileage of its largest, heaviest vehicles - recognizing that upcoming gas-mileage regulations will hit its lineup disproportionately hard

What lies in the more distant future? Automakers are tinkering with all sorts of combinations of fuels, including solar, electric, biodiesel, hydrogen, compressed natural gas and fuel-cell technology.

Further down the road, fuel cells will be the next big step in electric powered cars. Fuel cells safely create electricity from hydrogen in a chemical reaction - and that electricity is used to power the electric motor. The beauty of this technology is that the only thing coming out of the tailpipe is water vapor. But it also has some major drawbacks. Right now, fuel cells are incredibly expensive and complex. Then, there's the lack of a hydrogen fuel production and distribution infrastructure. And how do you get the hydrogen? Burn fossil fuels to split the "H2" off from the "O?" Some say it could cost $500,000 per filling station to install the necessary equipment. But since fuel-cell technology offers a lot of promise, expect to see some prototypes soon. Hyundai has been working on fuel-cell technology for years, and hopes to have fuel-cell production vehicles ready by 2012. Ford, GM and Honda are also testing their own fuel-cell vehicles. The Honda FCX sedan currently has an impressive 240-mile range and the Chrysler EcoVoyager sedan claims a range of more than 300 miles. Whether costs will come down enough for it to be a real production vehicle is yet to be known.

Toyota is working on a small, electric city car using lithium-ion batteries and a driving range of 50 miles. It'll be small - probably a two-seater. This new model could be available as early as fall 2011. Ford also has plans for battery-powered electric vehicles. The Transit Connect, a small van for businesses, is expected to arrive in EV form in 2011 and a sedan based on the Focus is scheduled for 2012.

The big question is whether other technologies will offer similar mileage and emissions cleanliness at lower prices. Right now, for example, you can still get a traditional gas-powered Honda Civic that gets almost 40 MPG on the highway, and costs several thousand dollars less than the hybrid version of the same exact car. That's a pretty good deal, especially if the majority of your driving is on the highway, where the hybrid technology provides minimal advantage.

Finally, there are diesel options. While still not as clean as a gasoline engine, the diesel VW Jetta does get over 40 MPG on the highway. "Flex-Fuel" (Ethanol/E85) cars offer another alternative. They're cheaper to produce and require low cost infrastructure changes at the pump. But, right now, ethanol fuel relies heavily on corn, which has gone through some wide price fluctuations - and is not an especially good fuel, from a global-warming perspective. Flex-fuel vehicles also burn more fuel than traditional gas-powered cars. These two factors make the cost savings for drivers minimal. There is hope that using various grasses and plant waste as a fuel source rather than corn will bring down the costs of cellulosic fuels. For more information, check out Car Talk's Alternative Fuels section. For people who want to do their part, without spending an extra couple grand, cars like these are providing serious competition to hybrids - alas, without any of the Ed Begley glamour.