Hybrid and alternative fuel vehicles.

I don't think the biodiesel will work very well. In order to make biodiesel, more people growing corn switch off to biodiesel. The price of corn, and everything based off corn (which is a lot) increase. People in South America who used to grow something else grow corn to take advantage of this price increase. The price of other crops increases. To create more supply, you need more farmland. How do you get that? Chop down the rain forest. Yes, biodiesel is cleaner, but not by much to offset that.

It's all here in this pamphlet: Time Magazine. ()

Brazil uses sugarcane, which is 6 times more economical than corn ethanol.

You can't grow it just anywhere, though.