Just thought I would include a few examples of off-the-shelf lights, custom SureFires, straight up custom lights, and so forth. :)
First up is a set of SureFire M2's that have had new LED modules dropped in. These are available from oveready.com, and are a slightly heavier-duty version of a SureFire C2, a very common light used as a base for upgrading. These lights, without an LED module, are about $120. A Malkoff M60 dropin is about $65.
They are a click on-click off light, giving you no option of variable output. It's all bright, 100% output, all the time. They're pushing 200-250 lumen out the front for about a 1 hour runtime on 2x CR123 batteries. To give you some perspective, that's bright enough to blind you at close distances. You don't want to accidentally bounce this off the mirror into your face, or let a small child play with it, because you can cause eye damage.
Something else to consider, also on the higher-end side of things, would be an HDS Ra Clicky light, available at hdssystems.com, for a smaller, almost as bright, programmable (variable) output light. It's more suited to go in your pocket all day, every day, and with it's variable output, will give you the option to read a map, read a book, pick up your wallet off of the floor of the movie theatre without blinding everyone around you - that sort of thing. Runs about $125-150 USD, but go to their website and have a look. One of my favourite lights available now.
Seen lower centre. The SureFire C2 is high centre, and two SureFire 6P's, all from Oveready.com, flank both lights.
Something to consider. Also runs on CR123's, but only needs one. Has a better runtime, at a slightly lower lumen output (which is arguably impossible to perceive with the human eye), and gives you that variable output I mentioned earlier.
Go to the websites. Read, learn, and buy. You'll find new uses for your flashlights every day, and wonder how you got by without them. :)