Just wanted to pass these finds along. They're great. Have tried many others. These are the only ones that meet and exceed expectations.
They have some unusual features.
They run on single Lithium 14500 (lithium ion, lithium iron phosphate, etc.) or NiMH AA or Alkaline AA batteries (among others).
They are waterproof and very compact, but very capable and bright when needed.
Unlike most LED lights, they have zero flicker (zero PWM). And no accompanying RF emissions and eye/brain fatigue. (You can test for flicker by passing a white pen or a finger back and forth quickly in front of an LED light in the dark. There is a strobe effect, or PWM, on most.)
They come in a variety of tints, including a neutral white (which is a warmer color than most LED lights; it's more like incandescent lighting), and a very mellow candlelight version (warm white) that's great for camp, tent, reading, dinners, etc. -- the only one I've found with this steady and mellow candlelight effect.
They have long run times (esp. using NiMH batteries on low, which is great for reading).
They are very well made, but the prices are reasonable. Much more so than most bike-specific lighting.
The best source I've found is EDCPlus. EDCPlus is very responsive, both with emails and with shipping. They shipped my order out the same Friday afternoon I placed it, and it arrived quickly. Good company to deal with.
These also come in blue and red, both anodized.
Some Ebay sellers are selling a previous version that does not have the "hidden" modes, and uses less efficient LEDs. EDCPlus has the latest versions, which also come with an improved switch.
The following additional version, the Xeno E15, has an extension tube which allows you to use two AAs, and it comes with a diffuser wand (the E15 may be also be available in tints not yet listed on the site, like neutral white):
The E03 is probably just as good as the E15 for most people's purposes.
For most of my uses, quality rechargeable NiMH AAs are the best battery choice, better than lithiums. The NiMHs give the best run times, on low, and the range of brightnesses is the most useful.
These lights give you an unusually wide range of brightnesses, from mellow, low candlelight (low setting, using NiMH AA batteries) to very bright (high brightness setting using AAs or AA-sized lithium-ions (also called 14500s) -- and in-between brightnesses as well, using other types of batteries (which give different voltages, and their corresponding brightness levels).
AA batteries are very widely available, including internationally; and it's nice not having to depend on 18650s or other hard-to-find batteries sometimes.
Sanyo makes some great rechargeable NiMH AAs (Eneloops, including the XX version). Amazon sells them.
You can also get clips that fit these lights. They allow you to clip the lights to visors, among other things. Then they become hands-free headlamps. The clips are available from shiningbeam.com (which has some good lights also).
(If that doesn't take you right there, you might have to do a search for "clip" within the site.)
Detachable clip for S-mini flashlight
The clip fits very well and securely.
These lights are also bright enough to use on the handlebars. Two Fish Unlimited makes a good, reliable handlebar mount that works well.
Hope this is useful to someone out there.