An intern at a website called Facebook (some sort of up and coming social network, whatever that is) took data from millions of friendships and drew a map using that information. He drew the cities where users were from and lines between cities depicting friendships. More details on how he drew this here.
It also shows to an extent the level of internet penetration in the world: not many users in Siberia nor the Sahara – or the level of internet censorship – can anyone see China?
High resolution image here.