Just saw this program call "Metro" (
http://nanika.net/metro/ )
Métro is your free guide on PDA (Palm, PocketPC, Smartphone...) to public transport systems worldwide (400 cities covered now).
Link to the list of covered cities
http://nanika.net/metro/MetroV-en.html
Looks like a really good application/database for public transportation networks and also include "Places of Interest" for some of the cities. And since the information/files are inside your phone memory, don't need Internet/phone connection.