Biofuels from agricultural products are a dead end. The real solution is biodiesel produced from algae. Algae can be farmed in the desert, using brackish water or even untreated sewage. It wouldn't require arable land and it doesnt have to compete with food.
The problem is one of economics. It is still cheaper to drill for oil...although if the cost of a military occupation in Iraq is factored in it really isnt any cheaper, its just that those costs are not being borne by the end consumer of the fuel but are intead being passed onto future generations in the form of debt.
If fossil fuel were taxed to pay for our military and eliminate the federal deficit, it could cost $8 or $9 a gallon. This would allow biofuels to compete on a level playing field. Combine that with a switch to diesel-electric hybrid vehicles that get 50-60 MPG, and we could be energy independent.
This technology already exists. It is simlply a matter of making it economically viable. Whether we like it or not, oil will run out one day. We need to start making changes now.