The Beam N Read is a battery-powered light that hangs around your neck. It shines light where you need it, on a book, ebook reader, map or keyboard. It's also good for close handwork, like knitting.
The basic version uses three LED bulbs and lasts for more than 100 hours. A Deluxe version has six bulbs and a clip-on magnifier. It also has a pair of color filters that can be used when you want to maintain night vision.
I found the Beam N Read to be a useful device when I'm outside doing night photography and I keep it handy for times when storms knock out the power to our house.
The basic Beam N Read costs about $20 at amazon.com, the six-bulb version about $30.