Luckily, Google Maps for mobile can give you the same public transit directions right on your cell phone! You can plan trips throughout the New York metro area, including turn-by-turn walking directions. With the My Location feature, most cell phones can automatically set the starting point for your trip, even without GPS. And satellite view and Street View (on selected devices) can show you a preview of where you're going.
With Google Maps for mobile in your pocket, you can go wherever the evening takes you, secure in the knowledge that it'll be easy to figure out how to get there. Google Maps for mobile with public transit directions is available for Blackberry, Windows Mobile, Symbian Series 60, and many Java-based phones. Download it by visiting http://m.google.com/nyc in your mobile phone's browser.
Link - from Google Mobile Blog