PRESTON, Idaho — Talk to a Preston resident for any length of time and you're likely to hear the town's new mantra: "There's a little bit of Napoleon in all of us," says lifelong resident Thedora Petterborg. "Who hasn't felt like that once in a while?" It's been several months since Napoleon Dynamite became America's favorite nerd. The movie, written and directed by freshman filmmaker Jared Hess and based in Preston, was a surprise success, grossing $44.5 million in the United States and gaining near cult status with December's release on...