This is map based on number of facebook users and their connections. It is interesting to see in which countries there are more online friendships. and how countries borders affect this online communities.
http://www.readwriteweb.com/archives/visualizing_a_world_of_facebook_connections.php?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+readwriteweb+%28ReadWriteWeb%29&utm_content=Google+Reader