Thanks to Today & Tomorrow for the tip and explanation !
An Amazing overview of the internet – The Web Trend Map 2009 by the Information Architects (IA) gives you the 333 most influential web domains and the 111 most influential internet people onto the Tokyo Metro map. The height of a station refers to its traffic, revenue and trend. Its width represents the stability of the company behind the domain. If it is positioned on a main line then it is a classic site and so on. See full size Map Here