If you’re on a budget have a look at Dealextreme
How cheap are these!! http://tinyurl.com/3egckh3
Helmet light (mines now on its second season)
Helmet mount (you needs this) http://tinyurl.com/3pltqm5
BTW i'd pay for the fast shipping!
If you've got some cash; I love the exposure lights with the cable free design and they've just released the 2012 model, so last years are in the sale here