I got a couple of these things when Nashbar had them on sale:
http://www.minourausa.com/english/ac...-e/lh50-e.html
They mount down on your fork, and I could put headlights on them. I don't think they're supposed to be used on carbon forks, though.
Now, I've got a hub generator light, but it's a skewer-mounted light, so it's also down low.