There is the Sony Wonder Technology Lab which opened last May, however this might be something you would want to do with the kids.
The Transit Museum is cheap and entertaining, and you don’t even have to leave Brooklyn. It’s at Boerum Pl and Schermerhorn St, around Borough Hall. I suggest taking the 4 or 5 to Borough Hall, then walking down Joralemon to Court St. Turn left on Court, down two blocks to Schermerhorn, then left and another block to Boerum Pl. (Those directions apply to coming from Manhattan. The F, G, A, C, 2, 3, and R also stop near here, so grab a map if one of those’d be easier.) The museum is easy to miss if you aren’t paying attention, because it’s in an old train station. The entry is the same as most of the stations – just a staircase in the ground. The museum takes about an hour, hour and a half, depending on how much you study everything.
The Museum of the Chinese in the Americas is fascinating. It’s late, and I can’t think well enough to describe the place, but I am glad not to have missed it. It’s at 70 Mulberry St, at Bayard. Take the R, W, N, Q, 6, J, M, or Z to Canal, then head east and turn right on Mulberry. Go down to Bayard, and it’s right there. Allow a couple hours for this one.
I also fourth (?) the Cloisters. Take the A train to 190th St, then the M4 bus (or walk) into the park from the train station. Beautiful collection of medieval artifacts in a reconstructed French cloister. My day there is one of my favorite memories of New York.
Zev, The museum of jewish heritage ( http://www.mjhnyc.org/index.htm ) is fantastic. The exhibit "Ours to Fight For: American Jews During the Second World War " was great - I went there a few months back with my grandfather, who was a Marine in WWII. It was amazing to see, read, and hear so many colorful and dramatic stories from the time. They have some short films playing as well, where guys tell stories of their experiences at the time, etc, which will help keep kids interested.
While you’re there, the Garden of Stones ( http://www.mjhnyc.org/visit_gardenofstones.htm ) is a must-see. It’s just outside the museum cafeteria (kosher of course!) and has the most amazing view of New York harbor, the Statue of Liberty, etc.
Hope this helps.
She was also in the Upright Citizen’s Brigade, which is where I know her from.
I also wanted to add a recommendation for the Tenement Museum, but I just saw on their website that they will be closed on Monday, so never mind.
Eva, chill. When I said it was funny, I meant it was funny. I wasn’t mocking you guys. Quite the contrary in fact – I think there have been some great ideas posted here. If anyone should be offended it’s Zev who needs non-natives to tell him what to do in his own hometown.
REminds me of a movie line:
[Crocodile Dundee]
Imagine that. Seven million people all wanting to live together. New Yorkers must be the friendliest people in the world.
[/Crocodile Dundee]
It’s a shame that the Tenement Museum is going to be closed, as that is a real treasure, IMO. You should try to visit sometime.
My partner was in NYC a few weeks ago, and she paid a visit to the Museum of Sex (recommended above by karomon). She had a great time.
Come up to my LOCATION, and hang around, waiting for opening day. 
There’s a very nice John Singer Sargent show going on at the Brooklyn Museum.
Also, a gallery of photos of Marilyn.
Hey all you people who want to go to Coney Island.
IT’S JANUARY AND IT’S COLD OUTSIDE.
And if you’re going to be outside, you might as well get up early, start your VCR recording, and go play in front of the windows on the national morning shows. (We don’t take any holidays off.)
Zev, FAO Schwarz, in its new incarnation, is geared towards unusual toys. You can’t find regular Monopoly, but you can get Mets Monopoly, or Giants Scrabble, or similar things. You can find toys for any budget, although they do have a factory to produce custom Hot Wheels cars at $20 each. That could be pricey. And avoid the $30,000 kiddie kars and expensive porcelain dolls.
Grand Central station is kinda cool. The food court has a decent selection, you can hunt around for the whispering corners (look for parabolic ceilings), notice that the starscape is painted backwards, and there’s often an art show or flea market-type thing going on.
Staten Island ferry to see Lady Liberty? Museum of the American Indian near Battery Park? Chelsea Piers? BowlMor?
I second the harbor cruise. It’s one of the few “touristy” things I really want to do when I visit in a few months.
Barbarian, what do the whispering corners do?
I wasn’t upset at all, really, just trying to make a point. I’m totally chilled.
There is an area with arched ceillings where you can stand in one corner, and your friend stands in the diagonally opposite corner 20 or 30 feet away.
You each face into the corner. Then you whisper, and the shape and acoustics of the room means that your friend can hear you at the other corner, as if you were standing right next to them. It’s really cool.
Ho, yus? Tell that to the old (Russian, I presumed) geezers I saw last week sunning themselves on the boardwalk!
Just remembered something else: Take the Tramway to Roosevelt Island. You can pretend you’re in Switzerland or somewhere Alpine. It’s $2 or you can use your MTA FunPass.
Bugger all to do when you get there, though. There might still be some smallpox spores milling around if you’re lucky.
Cold? Heck, I bicycled to work this morning; but Zev did say he wanted to stay indoors.
You could swing by the Hall of Science in Queens. But be warned: they close early in the afternoon.
It’s Monday. zev should be enjoying his adventure in the Big Apple. So what’d you wind up doing, zev?
zev? We’re still waiting to hear from you.