The convergence of rapid urbanization with the mobile tech boom has created a surge of young upstarts with one aim: make moving, living, and socializing in cities better and easier. So much so, in fact, that distracted pedestrians have become a real problem. Here, some standouts in portable urban tech, both shiny new apps and some veterans that played a key role in 2012. (Did we miss your favorite? Tell us in the comments.)
John Metcalfe contributed to this post.