Thanks to rising gas prices, there's been a big push toward alternative-fuel vehicles. From electric and biodiesel to natural gas and hydrogen, there are a number of options.
If you're thinking about switching, or if you're just curious about the technology, the U.S. Department of Energy's Alternative Fuels Data Center is a good starting point.
It covers all the alternative fuels available and gives an explanation of how each works. Plus, you can learn whether your area supports alternative fuels,whether there are tax credits available and what vehicles are on the market.