If you're ever in NYC over a Friday and you find yourself with some open time in the evening, you can head to the Museum of Modern Art (MOMA) for UNIQLO Free Friday nights from 4:00pm - 8:00pm. You can't buy tickets in advance so you have to go there and get in line - but I promise, even if it looks monstrous, the line moves pretty quickly once the doors open (or you can just get there a little later and miss the opening "rush")
It's terrific to be able to go and wander through the different galleries - Or you can just choose one exhibit or just walk around the building and admire the architecture. You can even get a free headset if you like to hear excerpts about some of the pieces that you're looking at. And because it's all free,(usual cost is $25), you don't have to feel guilty if you don't have a lot of time to spare and just want to visit briefly.
It's a great way to while away an hour or so without spending a dime.
11 West 53rd Street
New York, NY
Note: There is another location in Queens
Tip: If you can't get to the museum on Friday evening, you can go to the MOMA design/gift store directly across the street anytime for free (44 West 53rd Street) It's a great place to browse and find jewelry, furniture, accessories and gifts that reflect pieces from the museum.