Wikipedia: New York City Subway
Article about the New York City Subway, the most extensive public transportation system in the U.S. and one of the largest in the world.
Interactive Subway Maps
Interactive, Java-based map that plans a route on the New York City subway system.
Features New York City subway maps, schedules, guide to airports, and discount metro cards info.
Collection of photos from the other side of the tracks.
Abandoned Subway Stations
Complete inventory of existing underground stations in the metro area which are not in use.
Zurnet NYC: Zsubway
Bring the entire NYC subway line information to your iPod with Zsubway. Includes a demo, download instructions, and more.
NYC Transit Subway Map
Clickable map of the entire New York City subway system with detailed line information for each of the four boroughs that it covers -- Manhattan, Brooklyn, Queens, and the Bronx. From the Metropolitan Transportation Authority.