Nice (but HORRIBLE) graphic showing the trade-off that results from using food-for-fuel. 440 million MORE people (primarily the most vulnerable around the world) could be fed if we stopped this insane policy.

As seen at The Big Picture Agriculture....Here are a couple of graphics from THIS report by a private food id organization in Great Britain. I am sure they are biased BUT if even if these numbers 50% of the real impact, it is significant.

Using food for fuel is harmful in many ways, but the most harmful impact is no the food supply for the least of us in the world.  Support for corn-based bio-fuels is support for starvation at the margin (a quite a bit inside that margin).