Using virtual worlds to 'soft control' people's movements in the real one

Eighty-eight percent of Americans now own a cell phone, forming a massive network that offers scientists a wealth of information and an infinite number of new applications. With the help of these phone users -- and their devices' cameras, audio recorders, and other features -- researchers envision endless possibilities for gathering huge amounts of data, from services that collect user data to monitor noise pollution and air quality to applications that build maps from people's cell phone snapshots.