Obviously, if you're on Foursquare, the social network and phone app that allows you to "check in" wherever you are so that everyone basically knows exactly what you're doing at the given moment unless you leave a little room for mystery, you don't want to just check in every night at, like, the corner bar. Because people are watching, so you might as well posture accordingly! It's not surprising, then, that semi-fancy places like Balthazar and Brass Monkey are among the most checked-in spots in New York City by Foursquare users. Of course, these place are also relatively young and vaguely cool, as is Foursquare's target demographic.
Also on the list of most checked-in: Ikea, perhaps so friends can meet up in the Swedish meatball-serving cafeteria, Central Park, MoMA, the Met, the Brooklyn Museum, Café Grumpy, Bar Matchless, and Governors Island. So that's where New Yorkers want you to know they are the most, apparently — or just some of the most popular hang-outs in the first place.