Spokes NYC is a free iPhone application (available here) for New York City cyclists.  It generates ideal bike routes with turn by turn directions for cyclists within city limits.  Other features include a bike rack locator, bike shop locator, and the ability to report thefts from a given bike rack.  It is currently pending approval for distribution through the iPhone App Store.

Future features will include showing the safety of parking a bike in a given location (based on number of thefts), adding new bike racks that aren't currently cataloged, and suggested rides (for leisure). Other cities to follow (to be released as separate apps).