Nite Ize is currently offering an upgrade kit for those flashlights that you have laying around the house. The kit will replace the light bulb in your flashlight with an LED light. This upgrade kit will run you just $10 and can convert that rusty Mag-Lite you have sitting in the basement to a top-notch illuminator.
The upgrade will cause your flashlight to be brighter and what is even nicer is that it will give you 10 times the battery life. It is time to bring the Mag-Lite out of retirement.