You can get some great shots of Manhattan from Roosevelt Island. Otherwise there's not much to do. See my videos of Manhattan from Roosevelt Island. They are my first ones, so hope you don't get sea sick watching them.
Take the tram from TramPlaza at 59th Street and Second Avenue in Manhattan. http://www.ny.com/transportation/ri_tramway.html
Or if you prefer, take the F train from 63rd and Lexington towards Queens and get off at the first stop.
Lower Roosevelt Island has just opened up for visitors. The views from the lower part of the Island include western Queens, including L.I.C. and Manhattan's east side. The Island is situated on the Hudson River.
When you're visiting Manhattan, take a short subway ride (F train to Roosevelt Island) or tram ride (at 60th & 2nd Ave,) to this 265-acre jewel in the East River. You can walk around the island along the path by the seawall and find a tiny lighthouse at the north end and a landmark-protected ruin and undeveloped park at the south end.
This excursion will cost you $4, the price of a roundtrip on subway or tram.
This would be kind of fun and you would get a good aerial view of the city. I haven't worked up the courage to do it myself. You can probably get some good photos from here too.