Zsubway is a freeware application for Apple’s iPod that allows you to access and view the New York City subway timetable on your iPod. Zsubway contains over 300 color images showing each and every stop on every line, which trains run express and where they stop, which stops connect to which lines and hours of operation of the stops along your route.
It supports every type of iPod available in the market.

Download link and instructions- http://nyc.zurnet.com/subway/install/ via Digg