3-LED Dynamo-Powered Crank Flashlight
This is another great energy-efficient gadget to have around. It will NEVER need batteries. Great for camping (ever had your flashlight batteries die in the middle of the night?), hiking, and for car and power emergencies. All you have to do is wind it for about a minute, and you get an hour and a half of light. It's that easy! It's also lightweight and fits into a large pocket, so it won't bulk you down. Super bright and multiple brightness settings, too.
I recommend this as the backup/emergency flashlight and for once-in-a-while use, and for those who do not want to use batteries at all. It works well, but it takes at least a minute of winding to get a good charge. A minute of winding a crank with resistance is a long minute. I also have a small Maglite that takes AA batteries, and I use the newer Energizer rechargeables which last a long time and keep their charge over time. If you don't use the crank flashlight for a while it loses its charge.
Don't buy it. 5 years ago this was a great light. It had three rechargeable button batteries. (or capacitators). Now it has one, it's larger but won't hold a charge more than a minute. My old one is still going strong. I've tried three newer ones and they are just no good.