Originally considered a novelty item, The Flashlight has quickly become one of the world's most trusted tools. Each American owns an average of 3 or 4 flashlights, but providing light is not their only function. Join the National Geographic Channel to trace the flashlight's history and take a look at its unexpected role in our lives. From a military flashlight that can blind an enemy to crime-fighting flashlights used to find hidden clues, innovators continue to expand the flashlight's use.