The New York City subway system is one of the oldest in the world—and at times, it feels like it. Whereas other world cities have had, for years, electronic signage telling you when the next train is coming, New York's Metropolitan Transit Authority has been slow to roll this out, and only in certain stations.
As a result I've become like a parody of a Native American in a bad western, relying on the environment to tell me when the train is coming: You listen to hear the lines in the 3rd rail tightening; or wait to feel that sudden breeze on one side of your face that precedes the train's appearance; and more than once I've been walking over a sidewalk grate outside the station, then quickened my pace and barrelled down the steps after feeling that Marilyn-Monroe gust of wind coming up through the vent.
The MTA may finally be getting with it. This morning they released MTA Subway Time, a free app (a beta version for iDevices only, for now) that's hooked into the subway's electronic control center. You plug in the relevant station and it tells you how many minutes until the next train arrives. Maddeningly, for now it encompasses only seven subway lines, three of them being those useless trains on the west side (where I often forget that people actually live). There's no timetable as to when the rest of the lines will be added.
The MTA also announced they'll be making realtime train data available to third-party app developers, and they've released a browser-based version of the app as well, viewable here.