There have been several great Globe posts about lighting (see e.g. Jon, Matt's on BikeHacks, Brenda's, and the articles about the awesome MonkeyLectric lights on Totcycle and BikeHacks). I have not seen mention of these lights that the Rev. Dr. Teton Harry recently clued me into and that I just ordered for my Haul. The Reelights are batteryless, magnetic induction powered LED-based flashers. Some models have a small capacitor that stores enough juice to keep you visible while stopped at traffic signals. While their claim of "no resistance" seems to be in violation of the First Law of Thermodynamics, I do believe that their simplicity and lack of mechanical resistance gives them an advantage in both efficiency and reliability over typical generator systems. The Rev. Dr. Teton Harry and Swedish Christine sing the praises of these lights for their night journeys across Stockholm, and trust me, we need to listen to these people more.
Knee update: I'm off the crutches and am using a Bledsoe Brace for walking across snow and ice. A full rotation on the stationary bike became possible a few days ago, and suddenly I can think about actually riding again. Can't wait!