Interesting discussion. I read lots of news about new tech issues, and one thing that is very interesting is using algae grown in vertical 'beds' (for lack of a better term). This process produces vastly more vegetable matter per acre than any other agricultural method. In addition, algae is very high in vegetable oil, and after extracting the oil, the remains can be fermented into ethanol (or other alcohols, with gene modified bacteria).
Vertigro video
One other thing- ethanol isn't the best alcohol by any means. Butanol has higher energy density and lower solubility with water.
If the processes to get alternative fuels can be made profitable, they will continue to proliferate.