Just heard Daryl Hannah on a morning radio show talk about her car that runs on the oil used to cook french fries. You can actually take any car that uses diesel fuel and use the fry oil instead. It is the cleanest burning fuel available right now; of course it will be replaced when the hydrogen engine comes (whose only byproduct is clean, drinkable water). For older diesel vehicles, you just need to put in a different hose and add a small heater so that the oil doesn't coagulate. She also said that restaraunts actually pay you to take the oil off of their hands. I don't plan on trying this out, but it's still cool.