If you've never heard of Artbridge, just call it the Project Runway of street art. The non-profit is dedicated to taking construction scaffolding (otherwise known as sidewalk sheds) and turning them into temporary art exhibitions. If you've ever dreamed of seeing your art in a massive scale, get your ass in gear and submit your ideas to this year's call for entries. All submitted work is reviewed by a panel of artists (not Heidi Klum), and up to 25 winners will be selected to turn their sketches (or photos, digital art, collages, etc.) into billboard-sized installations hung outside for three months to a year. Inspired by the tons of blank scaffolding he saw each day, ArtBridge founder Rodney Durso wanted to "alter the city landscape and give a significant push to these emerging artists in an increasingly competitive art world." Plus, unlike Banksy, this street art is all legal.