There's a graphic post over on Green Wombat, about just how the US is in thrall to inefficent cars. It takes the stance that Silicon Valley is one of the most 'green' areas in California, yet they commute long distances daily in inefficent cars.
I'm going to say it again: There's little point in bothering with fuels based on feedstocks that have high alternative values such as biofuels built on corn ethanol until there is a serious improvement in US automotive fuel efficiency. Switching to biofuels simply leaves more expensive oil in the ground and pushes up the price of foodstuffs.