Convenience store, 7-11 / Bodega, Deli
Front porches are a hangout / Rooftops and Stoops are hangouts
Time Square is New York / Time Square is avoided and touristy
Even the way people interact with something as common as the subway is different. NYers hate when someone walks up or down the stairs of the subway station slowly - Move out of their way. People also have the ability to wake up at their stop - even though there usually is no announcement or it's an indecipherable dialect of New York-lish. Somewhere like Boston's T you would never see the things that you would see on the subway of New York - things like Mariachi Bands playing through the cars near Time Square, street preformers flipping down the train between Penn, and the ineveitable opening and closing of the car backdoors to someone with a sad story that beings "Ladies and Gentlemen, may I have your attention. I wasn't always this way...." asking for your donations and kindness.
NY subways are like no place else. But Wether it's the commute home or the commute out, the ride to Coney Island or to Queens (when you passed out at 5 am after a long night out only to wake up 10 stops past your stop) - the subway has a lot of stories.
Here's another cool NY Blog: http://missbinnyc.blogspot.com