A map of the world according to Facebook, from Dec. 13, 2010.

“Each line might represent a friendship made while travelling, a family member abroad, or an old college friend pulled away by the various forces of life,” Butler wrote in December.

But Butler’s maps aren’t the only ones out there that have used Facebook to analyze regional relationships.

The maps on Pete Warden’s blog, PeteSearch, may not have gathered as much attention online, but they are equally fascinating.

For example, his map of the United States reveals that the country has several distinct Facebook regions.

If you’re in the Northeast quadrant of the country, his data show you to settle near to home, and your friends do, too. Even New York City Facebook users tend to have long-distance friends in only one city, Los Angeles, followed by closer pals in D.C., New Jersey and Boston. Southerners tend to stick together. So do Mormons — a Facebook region around Utah is actually the only one completely surrounded by another region. Los Angeles also has its own little pocket, whereas the rest of the West has more far-flung friends.

The map also identifies some places with surprising regions: geographical neighbors Columbus, Ohio, and Charleston, W.V., have very few connections.

How varied would your Facebook map be?