I can sit at my desk in lower Manhatten and connect to 2 or 3 open APs that people leave around. One is named "free bandwith" so I guess they meant to do so.
You can literally war-walk in NYC, in addition to the places like Bryant Park (behind main branch NYC public library, 10 blocks south of Times Sq) or later this year the parks down near the WTC on the south end of the island.
I like a certain Starbucks where if you sit at the right table in the back you can pick up some guys open AP and not have to pay Starbucks for it.