Buy this

http://www.amazon.com/gp/aw/d/B005WPXNQ6

$25, an honest 600 lumens, a spot pattern, bright-less-flashing settings, will run for an hour or more if using less or flashing, rechargeable, easy to mount on the handlebars, can be wedged in a helmet vent and zip tied in place, waterproof, and did I mention only $25?

I use these for my commute, on my helmet, it lights up whatever you look at, and if you wave it over a car's windshield the driver will definitely notice.