Vivian Maier, who worked as a nanny, scoured the streets day and night, venturing into strange and sometimes dicey neighborhoods. Her constant companion was a camera. Over five decades, she shot tens of thousands of photos. Few were seen by anyone but her. That's the way she wanted it. But that's all changed now, thanks to John Maloof who stumbled upon a huge grocery box in an auction house, discovered her work and has now become her champion.–AP Photo