Woot is offering the LED Lenser H7 155 Lumen Headlamp for only $19.99. This is 67% off the list price, and the next lowest price is $7 more.

The headlamp has great ratings, snagging 4.5/5 stars from over 130 people at Amazon lightweight and can shine 180 meters for 4.5 hours. (Running on low will yield 20 meters of distance for 63 hours.)