Ditto, I use helmet lights as well. I started after noticing how much more visible other cyclists were when they wore helmet lights.

And I added a homebrewed doodad to my Light & Motion Urban 500 that both shades the top of the light from the eyes of oncoming cyclists/pedestrians, while enhancing the side visibility. It's just a white pill bottle of HDPE plastic, easy to trim to shape. It snaps into the recess just behind the lens, and can be rotated to suit how the light is mounted to the handlebar, head tube, under a computer, etc. I put black opaque tape across the top but left the sides open, so it glows like a soft white light bulb. Much better to-be-seen visibility all around.