If the recent documentary "Roger Corman: The Pope of Pop Cinema" left you with an itch for genre cinema that needs scratching, Popflick got the thing for you. "American Grindhouse" is an indie documentary by Elijah Brenner, offering a comprehensive overview of this cinematic phenomenon that flies against the traditional notions of cinema as fine art. It can be shoddy, dirty, dangerous, and thoroughly questionable. And yet, it is art.