This is better than a headlamp.
Who wants another piece of equipment to keep up with? Not me! I have had a headlamp in the past to get through to my duck hunting swamp and my deer stands. And the kind you strap onto your head suck.
I got the one that is built into my cap and it is awsome!!! I got mine from Dicks Sporting Goods but the Hat is called Panther Vision:
http://www.panthervision.com/
I love it. Just throw my cap on and I have my light.