Oh, and another neat thing about BioDiesel:

There's a company called Global Green (GGRN) that is developing a prototype algae-based bioreactor. It's basically a reactor that can be retrofitted to smokestacks so that the CO2 emissions are used to grow algae whose dried biomass is nearly 50% oil that can be used to produce BioDiesel. IIRC the yield per acre as about 1000 times that of soybeans.