According to the Department of Energy's EERE division (Energy Efficiency and Renewable Energy), alternative fuels, as defined by the Energy Policy Act of 1992 (EPAct), include ethanol, natural gas, propane, hydrogen, biodiesel (in it's 100% form), electricity, methanol, and p-series fuels. These fuels are being used worldwide in a variety of vehicle applications.
This website, and it's more specific sister sites, focuses on BioDiesel and E85 Fuel, a Ethenal-gas blend.
It is somewhat unrealistic at this time to believe that America's foreign oil dependency can be ended by using alternative fuels, but the ultimate end of this dependency is a worthy goal. When you add to this, the fact that alternative fuels like BioDiesel, M85 and E85 burn cleaner and create less pollution, it becomes obvious that the use of these biofuels is worth taking a look at.