Petzl Bindi

Ultralight and compact, the Bindi slips into a pocket and is ready when you need it.  It's got three lighting modes and red lighting for night use, plus the LOCK function keeps it from turning on accidentally in your pack.  You can tilt the lamp upward so you can see ahead while wearing it around your neck.  The rechargeable battery charges via micro USB port.

Ouput: 200 lumens 
Weight:  35 g
Modes:  proximity (5 lu), standard (100 lu), max power (200 lu) plus proximity and strobe red mode (1 lu)
Battery:  680 mAh rechargeable
Burn time:  50 hrs (proximity), 3 hrs (standard)
Weather protection:  IPX4