My good flashlight is a StreamLite... About 5inches long; $100+.
But my pocket flashlights are little 3" UltraFire flashlights; CREE LED bulbs; about $6. They use rechargeable 14500ah batteries that are about $3 each. I keep a couple of batteries in their charger.
The UltraFire isn't what I'd want for a very powerful light, but it light, small and bright. I have 4 of them that I keep laying around as well as one in my pocket most of the time. I call them "throw-aways" because they're so cheap, but so far after 2 years none have quit on me.
oh, and BTW, I have a slew of MagLites laying around. They're really dim compared to the UltraFire LED Cree lights, and eat up D-size batteries. They're obsolete these days, and are relegated to the bottom of a cabinet drawer.