One of our all-time favorite New York activities has to be the "Five Boro Bike Tour," also known as the New York Bike Tour and a few other names it doesn't really matter, the idea is the same and very simple: Bike all five boroughs in one go.
The route isn't that hard, the people are really nice, and really, how often to you get to bike over the Verrazano? The ride is on Sunday, May 7 so you've got lots of time to get ready. But in the meantime we always recommend registering early.
Cyclists from Oleg Dulin's flickr stream.