Mapping the Internet is actually a very popular thing to do. See also this "subway Map" of the Internet Mapped onto Tokyo's subway system: http://ia.net/blog/web-trend-Map-4-final-beta/
This 2009 "subway map" of the Internet is based on Tokyo's subway system. This design company (like a few others, I think) does one of these every year. It's a articular genre of a thing called an "infographic" that you see everywhere.
Geographic coverage of Wikipedia. This shows the geographical location of articles, a geographic features, etc. Mapping Wikipedia is a collaboration between TraceMedia and the Oxford Internet Institute.
I've added a new avatar for our course Diigo group. It's based on a 1974 map of ARPAnet, the first "network of networks," and thus the precursor of today's Internet. I got it from Wikimedia Commons, which is a great source for all kinds of media that you're allowed to reproduce on the Internet.