A good alternative to Surefires for everyday use, which uses 4 AA batteries, is the streamlight luxeon propolymer, not to be confused with the other streamlight propolymer, which is the same flashlight but with several dimmer leds. The luxeon propolymer is very bright, fully regulated, and can be found online for as little as $25(fox-international.com). I've had one for over a month and have yet to change the batteries, though I admit I've only used it for short periods. It's too big to EDC, but smaller than a C or D cell light, and a good size for general use.