A clever graphic / web designer has created a map of the internet based on Tokyo's subway map. Each train line represents a category (eCommerce, file sharing, games, politics, etc) and each subway station represents a website. The "stations" were placed on "lines" based on common "neighborhoods" that they share. In some cases the meaning of neighborhood names is clear - news, academia, open web, and in other cases they appear to be inside jokes. The more important a site is, the closer it is to the downtown core. I'm not sure what the criteria was for picking which sites made the map as stations - their blog just says "the most popular and influential sites". In any case, this is a fascinating way to visualize the web.
It's available as a click-able web map, a poster sized pdf file (takes awhile to download, but has the most detail), and as image files that are suitable as wallpaper for computer screens. The "Buy Now" button is only for ordering a printed poster copy. The electronic versions are free.