"[T]he emergence of more powerful, media-centric cellphones is accelerating humanity toward this vision of "augmented reality," where data from the network overlays your view of the real world. Already, developers are creating augmented reality applications and games for a variety of smartphones, so your phone's screen shows the real world overlaid with additional information such as the location of subway entrances, the price of houses, or Twitter messages that have been posted nearby. And publishers, moviemakers and toymakers have embraced a version of the technology to enhance their products and advertising campaigns."
Most augmented reality is being utilized for marketing efforts, but it can also be used in urban settings. One application, for example, uses the video feature of iPhones to display directions to the nearest New York subway stations.