Alternately, you could consider a 1AAA light like this one: http://www.shiningbeam.com/servlet/t...OS-Cree/Detail

9 grams plus a AAA. I zip-tied mine to my helmet facing rather downwards towards my bars, since my main use for it is to use the LOW mode to read my computer at night. If your goal is to be seen with it, then the larger lens area of the Princeton Tec will probably make it more "observable."

One other note, and you may already be aware of this: the one in the first post emits red light.