Daytime Lights: Best Thing I Ever Did
For anyone on the fence about whether to add daytime lights to your commuter, I just want to say that mine have added a much, much better sense of security to my rides, both to and from work. People clearly see me now and treat me like a moving vehicle, rather than just another annoying tree-hugger who's not in a car.
Don't even worry so much about WHICH headlight and tail light you buy; just do it.