Real Goods and a few other places are selling Biodiesel fuel refinery machines. They run 8-10k. Locally we now have a station that sells Biodiesel at one of it's pumps. I'm not sure that it is any cheaper at the pump, but the local refinery making it, uses mosted recycled fuels like oil from deep fat fryers and oil changes from cars, so it's a mix of stuff in there. As others will post here, to produce your own fuel source you are subject to taxes. I don't think people would get bent out of shape if it was just for your own use though!

I'm still waiting for diesel hybrids to make it on the car scene. I know they are trying this out, but haven't seen any for sale yet.