I'm completely fascinated by regional idiosyncrasies of ecology and culture. Every time I hear someone comment about how they associate some typical personality with some part of the country, I can't help but pin them down and try to figure out exactly what their impression is and how they came up with it.
Appropriately, Peter Warden created a map of the U.S. based on the connectivity of Facebook friends. He found that friendships in the U.S. form 7 major clusters, which he dubs...
The Northeast and Midwest, where people die in the town they were born. People mostly are friends with people in their own town and the next one over.
Same as above but as a separate cluster (which doesn't include southern Florida). People are very likely to have friends in Atlanta.
Includes Missouri and the Gulf Coast. People are very likely to have friends in Dallas.
People are very likely to have friends in all kinds of small and large towns throughout the entire western half of the country.
A little cluster inside the above, located appropriately.
LA is the hub of California, where Californians tend to be friends only with Californians (no surprise here).
People in Seattle apparently never go anywhere besides Seattle.
h/t: Edible Geography, PSFK