Design proposals are both promiscuous and frustrating. You see a good one, you get excited. And then nothing ever comes ot it.
Architects Brett Snyder and Irene Cheng didn't want those great ideas to go to waste, so they created "Museum of the Phantom City," a GPS-enabled iPhone app that shows you fantastical architectural proposals as you pass by various sites. If you amble past the World Trade Center site, for example, you'll see, among other things, a snippet of the proposal created by United Architects (a team composed of Foreign Office Architects, UN Studio, and Greg Lynn, among others) for Ground Zero (pictured above).
About 50 sites are included in the app. Snyder and Chang described it to The New York Times as a bit of sci-fi; a tour of the city's "alternate future," and a "a wall-less museum where the art isn't even there." While the typical iPhone app is designed expressly to waste time or save it, this one just tries to spark your imagination. Wonderfully, it's free.