Whoa! The New York Times has a 25-question survey that tries to discern where in the U.S. you live (or were raised) by how you pronounce words. They pegged me pretty good, as I live in the triangle plotted by the cities shown in the above map. Well, I actually live a little to the east, but there are no big cities there, and I did spend ten years in western Tennessee. The questions are based on the Harvard Dialect Survey. When you are through with the survey, you'll get a map like this, and three smaller maps showing which particular words were most instrumental in finding your home. How well did it find where you are from? -via Boing Boing
That said, I moved around almost constantly as a kid, and went to school in Missouri, so I've been exposed to so many dialects that I can use 'sunshower' and 'sneakers' on one hand, and then turn around and use 'y'all'.