The Google Maps API has been used to create a great Google Map of the Metro system in Tokyo, Japan. The map is completely bilingual and serves to help English and Japanese speaking riders. "Tokyo-Metro" and "Toei" Lines are sectioned off with the ability for you to select the routes within each line. Each station is then highlighted as a map pin so you can learn what transfers you can take in each one. Japan is a country that has seen the arrival of Google street maps, so you can toggle between street views (Japanese street labels only) and satellite viewing. There is even a "landmarks" toggle that lets you see notable locations such as Tokyo Tower, The Imperial Palace or Narita International Airport as they relate to the metro system. My description is only covering one of viewing interfaces! There is a completely different view with different functions if you click "Type 2" from the top of the map! This is a great Google Maps resource for people living in Tokyo, as well as for tourists visiting this great city!
Looking for more Google Maps mashups for Japan? Check here..