The new iPhone has true G.P.S. now, too, in addition to the fake G.P.S. of its predecessor — an ingenious system that shows your location on a map by analyzing nearby cellphone towers and Wi-Fi hot spots.

Unfortunately, there’s not much you can do with the G.P.S. According to Apple, the iPhone’s G.P.S. antenna is much too small to emulate the turn-by-turn navigation of a G.P.S. unit for a vehicle, for example.

Instead, all it can do at this point is track your position as you drive along, representing you as a blue dot sliding along the roads of the map. Even then, the metal of a car or the buildings of Manhattan are often enough to block the iPhone’s view of the sky, leaving it just as confused as you are.