Ultra Bright 2-Mode White LED Headlamp (2 x CR2016)

Pros: Genuine Nite Ize product -comes with Nite Ize branded batteries, good quality soldering and internal hardware. Emitter isn't your generic keychain LED, but obviously a custom molded plastic with exceptional clarity and an inverted dome that seems to put out light more efficiently.
Ran it for at least 8 hours off 2 CR2016's (literally, I just left it on my desk, didn't seem to be any dimmer when I checked again) , which if you buy them from places like DX is a major plus since they're cheap, flat, and compact.
Gives me enough light to set up my backpacking tent, but I can deal with low light levels so mileage may vary for you.
Seems to be fairly weather resistant with the way the flexible rubber front closes over the base, but probably not water-proof if submerged.
Pushing it twice turns it on to a flashing signal mode that my friend said was very noticeable at 200 yards off in total darkness.
Like a lot of the small LED stuff Nite Ize puts out it seems to adhere to the philosophy of simplicity in design.
I'm buying more and sticking one everywhere.

Cons: This isn't really a con to me since I can work with it and I bought this wanting something simple reliable and solid, but its not the brightest. I have enough light to perform basic stuff like setting up a tent with or navigate in the dark so fine by me.

Other: Buy one, for your car, one for your backpack. Takes up almost NO space and weighs nothing. Great to see in the dark during a power outage or disaster or just if you're camping and don't want to be burning AAA's or 18650's all the time.

Pros: "Water resistant", sealed unit (the whole front of it pops off (2 piece construction). So would stand up to wearing in rain, getting a bit wet. But it is genuine nite ize, and good quality. Comes with 2 sets of batteries.

Cons: Price. There are more powerful, cheaper headlamps on DX.

Other: You will really regret not one of these if you ever break down on the highway at night and have to fix something on your car holding a flashlight in the dark.

Pros: This is a nice headlamp, in a decent price. Easy enough to operate, just one click. Easy to adjust to head size. Produces strong white light.

Cons: It's not like a flashlight, it does not 'shoot' the light forward. It's more like a night lamp: the light spreads all around. So, I could not use it to see what's in front of me! It's only good if I want other people to see me in the dark.

Other: I do not find it useful.