With more than 350 cities covered, Metro is the ultimate public transport guide for your PDA and smartphone. It will help and guide you through the metro areas around the world. Some of the features include route computation, contact list, places of interest, line (transport) details and more.
The sad thing about Metro, is that the Symbian version only supports 6 cities – Amsterdam, London, New York, Paris and Tokyo (at least in my test on a Symbian S60 device – picture bellow is from Nokia Communicator).

Metro is free and it works on Symbian Series 80 (Nokia Communicators), Series 90 (Nokia 7710), UIQ and S60 (including S60 3rd edition) devices. The UIQ 3 version is still not available, but as they update Metro pretty regularly, I’m sure we can expect it very soon.