food vs. fuel

here's an interesting comparison chart relevant to our recent discussions in class:

We've been talking about various renewable sources of energy, which brings up the food vs. fuel debate.

at what point does growing food for biomass (biofuels) take away from growing food for people who can't get enough (the homeless/hungry in our own country as well as third-world countries without sustainable food production)?

Here's a PDF from the institute for agriculture and trade policy about the production of ethanol and the issue of aggravating hunger/poverty. It claims that the US production of biofuels will NOT further hunger/poverty... while this article seems to feel the benefit of this technology is debatable.
I think that the production of biofuels have the potential to work, but currently the process is unsustainable. In the next few years, however, I sense an onslaught of technology for alterative energy sources... But clearing miles and miles of excess land to grow ethanol (the current amount of US crop land, as seen in the chart, isn't even close to meeting half our energy needs) is simply adding onto the problem..