The Roosevelt Island Tramway is a low cost way to grab some nice ariel photos of the Upper East Side, Downtown Manhattan and Queens.

Price of admission is a swipe of a New York City MTA Metrocard.  Similar to the Staten Island Ferry, once you arrive you must exit before taking the tram back to Manhattan.  However, I would recommend you spend a little time on Roosevelt Island.  The island has busses to get around but is also easily walked.  Visitors can also bring their bikes on the tram for a quick ride around the island as well.