E85. Grown from corn, and it iwll work in MOST vehicles in MOST situations.
You just have to adjust the spark timing and air-fuel ratios for it. A couple of other minor things but for the most part it runs fine.
It's for the most part, fairly viable. I'm toying around with getting my new motor built for a high-compression E85 fuel.
Unfortunately, the gas mileage isnt any better, it's actually a little worse. But it wold reduce our dependence on OPEC a lot, and support American farmers. And since it's not comprised of mostly finite resources it would hopefully lead to less price-gouging. But the realist in me says we would just be switching one master for another. But at least this way we're not funding the middle-eastern terorrist oil baron regimes.
There are reasons people speculate it wont work, I think they're wrong. Brazil has been running all their cars on Ethanol made from sugar cane for 20-30 years now I believe.