Metroid is an Android itinerary planning application meant to help users with public transportation systems worldwide.

Further release notes:

Our ambition is to make Metroid, a must have for Android users traveling around the globe. We are committed to support as many cities as possible. Metroid has been designed with extensibility in mind. It is able to support any public transportation system provided that the right map is available.

Metroid is based on maps. A map encapsulates all data about a city : transportation lines, frequency, stops… Metroid maps are based on a very simple text based format. The map data will be mainly contributed by the community. A special utility has been created to turn the map data into a compact and efficient format to be transfered and used on android devices. Based on that open approach, virtually every city in the world will be supported. At the moment 7 cities are supported : Paris,San Francisco,Milan, Washington and Atlanta. Many more to come.

http://code.google.com/p/metroid/