Facebook engineering intern Paul Butler has created a map of the world based only on Facebook friendships. Each line corresponds to a friendship and the brighter the lines, the more friendships there are between the two points. So the border lines of the world's land masses are actually created by the friendships. As Butler himself says, "what really struck me…was knowing that the lines didn't represent coasts or rivers or political borders, but real human relationships... Each line might represent a friendship made while traveling, a family member abroad, or an old college friend pulled away by the various forces of life." Got the warm fuzzies yet? [via The Guardian]