Alright, I am pleading for help. Choosing lights is proving harder than choosing a bike... I have on order one of the 9 LED taillights from Dealextreme for a steady tail light, and I just bought a Mars 3.0 for a blinking rear light (I was leaning towards the Superflash but those were out of stock at the moment of truth).
For headlights: I'll be using them for commuting on suburban/somewhat urban roads with decent to poor lighting. Here's my summary of various options that I'm working on right now...
Commercial HID: Too much $$$, convenient and bright.
Commercial bike LEDs: $$$, not that cost effective
LED Flashlights: $, bright, may have to juggle lots of small batteries
MR16 halogen, 13.2 or 14.4V: $, very bright, simple using Optronics housing, need a large battery, perhaps less reliable.
I'll probably buy one of the popular Ultrafire flashlights from dealextreme soon as a starting point. The ideal solution for me would be something simple based on a couple of the Cree LED emitters, combined with a single external battery pack - in other words something basically equivalent to the MR16 solution but without the filament. Does something like this already exist? Are the LEDs mounted in the MR16 housings worth looking at?
I am more than capable of fabbing my own DIY LED lighting system, with a background in optical design and ready access at work to a milling machine and lathe, but I just haven't had the free time to consider that route so I'll table that option for now.