Look up the ITP A2. I think that model may have been renamed, but looks like they are still available under that name (a Q5 at Battery Junction for $25, fer example.) I got one from Shiningbeam a couple of years ago, and like it a lot. (I like the A3 even more, because it's so tiny, but I agree with those who say get an AA light only for best battery availability. Also, AA are cheaper per watt-hour.) Nice three mode light. The PWM is fast enough that it's not usually intrusive. Mine has a neutral-white emitter, which is great if you can find one. I ditched the metal lobster claw and just made a lanyard of 1/8" cord tied through the split-ring. Biggest drawbacks: won't tailstand; twisty switch so a little tricky to operate one-handed.
I made a headband out of neoprene with little pockets on each side, one which holds an AAA light or a small AA light (the A2 barely fits) and the other sized for medium to large AA lights. The only problem I've noticed is that if you wear glasses, having the light on the side of your head give reflected glare off the back of the glasses. With a single cell light, it's hard to pull the light far enough forward to prevent this.
Another neat 1xAA light is the Romisen RC-29, which has an aspheric zoom. The uniform illumination at wide angle is great, and it must be one of the best throwing 1xAAs at full zoom. A few drawbacks: 1. single mode, so would often be producing more light than needed and eats cells fast. Fresh eneloop lasts almost exactly an hour. An alkaline would be a lot less. 2. weird little sharp fins around clicky make for a good tail-stand, but can be a little uncomfortable in a pocket and make it difficult to slip into the headband mentioned above without removing the tail switch. The zoom head is quite a bit bulkier than a small reflector head like the ITP, of course.