Best kept warm to enlighten. It's not me I am talking about. It's the "Hollow Flashlight", an invention by a 15 years old Canadian high school student, Ann Makosinski, that lighted up by the warmth of her hand holding it.
Here is a video of her talking about her submission of the "Hollow Flashlight" for the Google Science Fair.
No batteries required? Definitely, the torchlight of the future to have.