Many alternative fuels are being used today in place of fossil fuels like oil. The U.S. Department of Energy classifies the following fuels as "alternatives" to gasoline: biodiesel, electric fuel, ethanol, hydrogen, methanol, natural gas, propane, p-series, and solar fuel. Below are links to the Alternative Fuels Data Center where you can find more detailed information about each specific fuel:
Advanced Vehicles & Fuels