A graduate student did a nationwide survey of how people pronounce words, or use certain words to describe things. He compiled them into heatmaps of the country, and the results are awesome.
My favorite, of course, is the map about whether people say “soda”, “pop”, or “coke”.
Check out my hometown of St. Louis, which is clearly a hot spot of “soda” in the midst of a bunch of hicks who say “pop” and “coke”. Nice!