The Knog Boomer is one of the slickest head lights out there. It attaches to your handlebars using it's stretchy body. The super-bright LED puts out 50 lumens of light. It has four modes: constant, strobe, fast flash, and random strobe. It's bright, lasts long, looks good, and is easy on easy off, all at an affordable price.
This particular Knog Boomer is USB rechargeable. Instead of buying a bunch of batteries, just plug it into any USB port. Pretty cool, very green!
Note: You only get one light. If you want that nice looking rear light in the picture, you have to buy that separately.