fyi, there are also mounts for mounting a light on the fork. Like this one -


I can't link to it directly, go to http://www.peterwhitecycles.com/b&m.asp and search for the text "This new mount puts the Ixon Speed, Ixon IQ Speed, Big Bang or Ixon right above the front tire at the fork crown." and it's right above it. You have to call them to order it - the mount is $3.

You install it right behind the brake, between the brake and the actual fork. The one drawback is that it made my brake a little less...futzier. There might be other, similar ones as well. fyi.