I ride mostly on inner city streets that are lighted well enough that a "steady" light adds very little to my ability to see the road. My biggest concern is that drivers notice me. In the inner city, there are always dozens, or hundreds of lights and distractions for drivers, and a tiny "steady beam" bike headlight can get lost in the urban chaos.
I have been using blinking LED lights to increase the odds of being noticed. A couple of weeks ago, I got a SIGMA three LED flashing strobe that uses three AA batteries. I KNOW cars and pedestrians see this light. It annoys drivers enough that some drivers will flash their bright lights at me. I have heard comments from pedestrians who were about to step off the curb and were startled by the intensity of the LED.
It was only $19 at my neighborhood LBS. I'm thinking of buying some more of the SIGMA's and run a pair of them on each bike...an opportunity to be twice as annoying to motorists.