Some of these ideas are not just for the serious prepper, but for general use such as camping, or in a situation where you need more light. I know a dark house is terrible to navigate during a power outage, and you are trying to take your child to the bathroom and hold a flash light. This is a very cool idea. You can take a gallon water jug, filled with water of course, and place your headlamp around it with the light facing toward the water. The light will flow through the water and illuminate the entire jug providing a virtual light bulb.