towards someone on a 2-way bike path whose lights are so bright I can't see anything because it's burning out my retinas) but they flash, which is better for car visibility anyway. I use the same Planet Bike ones mentioned below. I have a friend who outfitted his bike with a Hub Dynamo and lights that run off of that power. He says he can barey feel the extra resistance (and only when the lights are on), and the lights are plenty bright. And he will never need to buy batteries or charge his lights. It did cost him I think a few benjamins, and a hub-based system means you need to replace a wheel, or at least rebuild/relace, which is not a trivial process. But it sure beats the old-fashioned generator riding on the side of your tire, I had one of those when I was a paperboy, and what a DRAG (literally!) I've used a hub dynamo system for the past two years. Mine is a German-make -- Busch + Muller -- and it replaced the wheel dynamo by the same manufacturer, which I used without a problem for about seven years. To use this system, I had to learn how to build a wheel, a process which was its own barrel of fun, and increased my confidence that I can fix one more thing on my bike. (But you can buy them installed.) The system turns on or off with a single switch on the front light