Google is out today with an announcement that Google Transit is now available on your mobile device. It can also work with your "my location" feature that will pinpoint where you are located as a starting point. Google Transit works in about 50 cities around the world.

It’s pretty impressive — you can zoom in and see exactly where the bus stop is on the corner, find out when the first or last trip is each day, and find directions from and to anywhere in the cities that Google Transit is available.

What would be cool is a "re-route" function so when a bus or train is out of service, you can select that the system shows you routes without a specific option. 

To get Google Maps/Transit, go to this site on your mobile device: http://www.google.com/gmm