Took the plunge - ordered a Trail-Tech HID light (chassis mount version, not helmet mount; I'm a commuter not a trail rider) and NiMH bottle battery from batteryspace.com yesterday. Also I ordered a 56-LED truck brake light from superbrightleds.com

I have a Planet Bike 1W Luxeon Super Spot, a 1W luxeon flashlight, a Cateye 3-LED head lamp and a 20W halogen light; when I get them all together I'll see about posting comparison photos. They're coming ground so they won't be here until next week. This should be enough time for me to do all my DIY before I SERIOUSLY need lighting (I have been in the dark in the morning, but dawn is cracking by the time I get to the busier streets).

I'm thinking I'm going to set up the truck light to run in "tail light" mode constantly, and use the high power 'brake" light in a strobed configuration (driving it with a 555 or microcontroller, depending on if I want fancy flash patterns).