I wanted to chime in on this light...
I was just going through my old EDC lights and am going to bring this guy back into rotation...
This single AA "River Rock" 1W light I bought at Target 3 or 4 years ago for around $20 has just been a great light and has never done me wrong...
It's a reverse-clicky, which I'm usually not fond of, but it's been 100% reliable and has never turned itself on in my pocket. If you really need momentary, you can click it on, then back the tailcap off until it barely turns off, then press the cap in until it lights, just using the play in the threads. Tailstands perfectly, lens has held up beautifully without any serious damage despite daily pocket carry for a a few years until getting replaced by my Novatac (which has had a few tailcap hiccups and cost 4 times as much!).
If you get a chance to pick up one of these, they are great EDC lights. Works fine on a Nimh rechargeable AA. (currently using 2100mah ones from Radio Shack)
It's pretty bright for a single AA, to my eyes about even with my Novatac on its medium setting.
I'm not saying other lights aren't worth it, I love good classy quality gear, but this light has been good to me and I had to share!