André J. Hermann is a photo-geek’s Santa Claus, hiding a number of his photo books around San Francisco and leaving clues for his Internet followers to find them. Each book is a unique collection of Hermann’s Instagram photos. So far there are only 2 left undiscovered out of the original 12 Hermann hid. The artist says he’s “challenging people to get up and get out” Hermann will be in New York City this August to conduct the same experiment with a different set of photos. [NewYorkTimes]