As part of my growing flash light fetish, I picked up the Surefire Executive Defender E2D flashlight. It's a small flash light that fits in the palm of your hand but provides serious utility.
At 60 lumens of brightness, it will light a dark area extremely well. It is also designed for self-defense with enough brightness to blind an assailant immediately. The front and back are reinforced with a very very solid steel that is slightly surrated to ensure that anyone you whack it with takes some serious damage.
While not something I would personally use for defense in all likelyhood, as a last resort, it's better than nothing. In the meantime, I'll use it as a handy way of getting around in the dark.