The last segment of the episode of 'Dirty Jobs' I watched tonight was on making biodiesel. I loved it! Now granted, the hobbyist who was making his own veggie fuel had his own complete refining and processing setup in his own garage, so he wasn't just taking the straight veggie oil and just filtering it. No, this guy was going along and adding in all the easily available additives needed to run his diesel powered vehicles 100% off of veggie, as well as run his home's oil heating system off of veggie as well. Not totally 'free', but the hobbyist had done the math and computed that with getting his restaraunt-fresh waste oil for free, his home refining costs had amounted to where he was paying $0.55 a gallon for his biodiesel for both powering his vehicles and heating his home. Still awesomely cheap! Cheap as gas was back when my parents were kids!