Google Transit
Get directions on public transit for cities around the world.
www.google.com/transit
HopStop.com
Public transit directions for several U.S. cities.
www.hopstop.com
Public Transportation
Links to public transit systems around the U.S., news and information about public transportation, and a calculator to help you figure out how much money you can save by using public transit.
www.publictransportation.org