It turns out the food or fuel competition over corn may be a much more serious and immediate problem than anyone realized. Lester R. Brown of the Earth Policy Institute writes:

World May Be Facing Highest Grain Prices in History

Investment in fuel ethanol distilleries has soared since the late-2005 oil price hikes, but data collection in this fast-changing sector has fallen behind. Because of inadequate data collection on the number of new plants under construction, the quantity of grain that will be needed for fuel ethanol distilleries has been vastly understated. Farmers, feeders, food processors, ethanol investors, and grain-importing countries are basing decisions on incomplete data.

The U.S. Department of Agriculture (USDA) projects that distilleries will require only 60 million tons of corn from the 2008 harvest. But here at the Earth Policy Institute (EPI), we estimate that distilleries will need 139 million tons . . . half the 2008 harvest projected by USDA.
. . .
This unprecedented diversion of the world’s leading grain crop to the production of fuel will affect food prices everywhere. As the world corn price rises, so too do those of wheat and rice, both because of consumer substitution among grains and because the crops compete for land. Both corn and wheat futures were already trading at 10-year highs in late 2006.

The U.S. corn crop, accounting for 40 percent of the global harvest and supplying 70 percent of the world’s corn exports, looms large in the world food economy. Annual U.S. corn exports of some 55 million tons account for nearly one fourth of world grain exports. The corn harvest of Iowa alone, which edges out Illinois as the leading producer, exceeds the entire grain harvest of Canada. Substantially reducing this export flow would send shock waves throughout the world economy.
. . .
And this soaring demand for corn comes when world grain production has fallen below consumption in six of the last seven years, dropping grain stocks to their lowest level in 34 years.
. . .
The grain it takes to fill a 25-gallon tank with ethanol just once will feed one person for a whole year. (emphasis mine)
. . .
Soaring food prices could lead to urban food riots in scores of lower-income countries that rely on grain imports, such as Indonesia, Egypt, Algeria, Nigeria, and Mexico.

Already, the price of Mexico’s staple food, corn tortillas, has increased 400%.