Several years ago, it was reported in the news that some organization had "mapped the entire Internet" -- i.e. they had mapped IPs to geographical locations. I don't remember the organization that originally did this, but there are several Internet mapping projects.
http://research.lumeta.com/ches/map/index.html would be a good place to look -- this Internet mapping project's site has several links to other projects (also try http://www.cybergeography.org).
