Ethanol
A great article by Robert Samuelson of Newsweek about President Bush's plan to decrease gasoline consumption. While it is a great goal, the means is via huge government subsidies, when all that is really needed is requiring vehicles to get better mileage (rather than just passenger cars like the proposed scheme):
I would propose that any vehicle (car, truck, SUV, whatever, no exceptions) that gets less than 25 miles per gallon should have a $3,000 tax assessed. Any car that gets over 45 miles per gallon should get a $3,000 tax credit. Those numbers would have to be adjusted to make sure that the two balance each other out, but that's probably a decent start. It would cost the government nothing and instantly result in people buying cars with 80% better mileage.
My post in 2003 on Green Cars