Today’s New York Times carries a fascinating study on how large numbers of users walking around with mobile phones, constituting a cheap sensor network. Urban planners, technology companies and officials from local governments see potential in projects like these that mine data collected from phones to provide better public services. Boston is developing a system called Street Bump that uses a smartphone’s accelerometer and GPS system to detect when a driver hits a pothole and then sends that information to city officials. Techniques like this may help cities collect data that until recently would have required expensive network sensors.