pickles are soooo much more important than oil, there would be no dissent about the war if iraq produced pickles, we americans love pickles, and cheese! :)
no but seriously, the grease instead of diesel idea is great for hobbyists, but this isn't practical, this is far too complicated for a mass market.
Hybrids, ethanol, and hydrogen are all irrelevant, the American auto market is going to be 99% electric by 2025. This is a better solution because the energy becomes more portable, and the most expensive parts of the infrastructure are already in place. Will it be green? no. but it's much easier to convert one power plant to solar or nuclear or wind, than it is to convert 300 million americans to hybrids and then to ethanol and then to hydrogen and then to nuclear and then to photovoltaic and then to quantum wierdness.
The change is here, expect it soon. the future is electric