This USB LED torch is an easy project for beginners in electronics and requires some soldering. The torch can be used as a conventional torch or an emergency light during mains power failure.
It can be powered from any USB host port. The image below shows a USB power pack that is sold as a solution for charging USB devices on the go. If you already have a USB power pack, the USB torch can be built for very little cost and carried with you wherever you take your power pack.
The torch is shown below powered on.
The article on how to build the torch includes a circuit diagram and parts list.