I rushed out and bought this innovative product — a Nalgene bottle lantern — as soon as I heard about.
Having used it on my last hiking trip, my score is 2.0 out of 10.
A great idea, very badly executed.
There are several problems:
• special tool needed to attach the lantern lid to the bottle
• special screwdriver needed to change batteries
• it’s too heavy
• you are asked NOT to put the top in water
• it gives surprisingly little light
Would someone please manufacture a light-weight, washable version?
(It’s a water bottle, for cripes sake!)
And how many people are going to carry special tools for it on the trail?
(I actually had one. The eyeglass screwdriver from my Swiss Army Knife worked.)
==== original post March 20, 2007
gear I need NOW – water bottle lantern
This nifty little device acts first as the lid to a bottle of water. Press a button, however, and the lid emits an “integrated LED light” which turns the water bottle into an instant lantern. Hang it from a tree and you’ve got enough light to play that game of cards around the campfire.
Things can get really funky if the bottle is full of green Gatorade or pink lemonade. Just don’t fill it full of chunky soup.
Price: US$21.95
besthike.com 
Maybe neato for the family who camps in the National Park or State Park campground on the weekend or summer vacation?