I've covered several solar gadgets here on GO, but it's important to promote the value of some kinetic energy-based products as well. One such cool device that I found while stumbling the green web is the Eco LED Flashlight.
Instead of having the shakes to produce energy (like most other eco-friendly lights out there) this product uses a zip cord. Simply pull the cord for about a minute — and voila! — you've got enough light for nearly half an hour. Pull longer, and that time limit goes up and up — to almost 45 minutes. Thankfully, the flashlight also comes with a car charger so your savings in batteries don't go towards physical therapy for your arm. Powering directly will yield you almost 3.5 hours of use. Did I mention it has a swivel head?
The good times don't stop there. Not only can all that physical exertion give you enough light to reenact The Blair Witch Project, but the power stored can also charge up any number of devices. The Eco LED comes with several adapters for PDAs, cell phones, and a host of other electronics. The 5 LEDs will last roughly 50,000 hours, so expect this flashlight to help you out where others have let you down.
For piece of mind in your glove box, boat, camping gear, or home, I'm not sure you can go wrong with this gadget. For $29.95, "zip" on over and pick one up!