The term "grindhouse" has been thrown around so casually lately, including its use as a title for a Quentin Tarantino/Robert Rodriguez film collaboration, that its meaning has become a little obscured. The documentary American Grindhouse looks to change that, with an exploration of the rich history of grindhouse theaters and exploitation filmmaking. It shows exclusively this weekend at the Sci Fi Center, the closest thing we have in Vegas to a modern-day grindhouse theater.