Small, handy, lightweight light - Streamlight MicroStream LED Pen Light w/ 45 Lumen Output

The Streamlight Microstream is a surprisingly powerful for its size, and it runs on readily-available AA batteries. It has a button-switch on the end-cap for easy one-hand activation, and it comes with a handy lanyard so that you can hang it around your neck when you need to have both hands free. It's a great little light to keep in your pocket all the time for those moments when you unexpectedly need a light.