Anthony Townsend started thinking about the intersection of technology and cities before the rest of us knew such a place existed. Back in 2002, when carrying a telephone in your pocket still felt slightly cutting-edge, Townsend, with the volunteer labor of civic hackers and donated equipment, was helping to blanket New York City's Bryant Park with 10 acres of free wireless Internet.

Today, Townsend is a research director at the Institute for the Future and a fellow at NYU's Rudin Center for Transportation, and the rest of us have caught up. “Smart cities” is a hot topic, and with good reason. Cities are awash in data. Our gadgets have grown incredibly small and cheap. Not only might a city tree be equipped with a sensor that knows when it needs watering, but it might connect to a software system that checks a summer concert schedule and beams a work order to a Parks Department truck.