This is so *barely* MYOG but it seemed to fit better than other forums...please accept this humble use of an otherwise cheese-whiz item...
I attended a conference and got one of these hand-crank LED lights...two LEDs, not that bright, and has an on-off switch, so that it will stay on without being held. After 30 seconds of cranking it seems to hold 30-45 minutes of usable light...not bad in a pinch.
It weighs exactly one ounce. Not as light as the Photo Freedom Micro, but it never needs batteries of any sort. In bulk they sell for about $6.
I decided to make a backup headlamp out of it...it'd be tough to use for navigation, but it's decent for a task light, and it's the ultimate backup in that you never need to worry about power.
I did so by simply gaffer-taping the smallest binder clips that I could find to the top of it, so that it would fit onto the brim of a baseball cap. (Hint: That binder clip weighs less than the Photon Freedom Micro's fancy-schmancy clip!)
And oh so eco-friendly compared to batteries! :-p