Brew your own fuel? E-Fuel claims you can obtain about 1 gallon of ethanol from 10 gallons of sugar and the price of the device ($9,995) can be offset by federal, state and local credits. They also claim you can obtain raw sugar below $1 through a system of carbon trading coupons.
Thomas Quinn, founder and CEO of E-Fuel, claims that this ethanol can be used straight in your car, without further modifications, or even mixed 70/30 percent with water or gasoline.
[Source: Popular Mechanics (thanks to Matt for the tip)]