Taking Back the Streets

New York's streets are as gritty as the city's reputation, traffic-clogged canyons of concrete where jaded foot-travelers and cyclists jostle and growl, exulting all the while. (Stared down a Hummer lately?) Yet street reformers from around the globe are increasingly turning to the city's 5,800 miles of streets, sidewalks, and highways, dreaming up ideas -- be they modest or unbound -- to radically transform the urban experience. Here are ten mutinous proposals.