Check out this map, just posted by Slate ("Dinner at the Kwik-E-Mart"), showing the placement of the so-called Food Deserts of America. A lovely term, really, which sounds more like a Ben Marcus short story than the USDA category which it is. According to the US Department of Agriculture, 2.3 million households do not have access to a car and live more than a mile from a supermarket, which puts them precisely in these metaphorically arid pockets.
With so much of the national food discussion centering on health care, obesity rates, and government policing of the country's food supplies (President Obama signed the Food Safety Bill yesterday), it's interesting to check out the practical demographics. When your food options do not include the beautiful stalls of a nearby organic farmers market but one of two convenience stores, the world is a very different place.