Check out how a couple of New Hampshire college kids spent their summer vacation—in a grease car! Follow the adventures of Justin and Skip at http://www.greasecar.com. They drove across the country in a '82 Volkswagen Westfalia fueled by vegetable cooking oil they picked up from restaurants along the way.
Their site describes and shows the conversion of the van to a diesel engine, which runs on anything from bacon grease to canola oil. The car is started using diesel fuel until the "oil" tank is heated. By flipping a switch, the car putts along at the speed limit on the former fry fixins'. Each night before fueling their own bodies, the two flip the switch and run on diesel to flush out the lines.
They started cross country on June 30 and were home in time to make their first class. But the road wasn't smooth. Early in the trip, they had to replace a muffler and the engine (check out the site for full details), but this attempt to go cross-country may open new doors to using and recycling this bio-waste product with a simple retro-fit kit. Do you want to supersize your order?