Just a heads-up on an item in today's The Tennessee (9/9/05) of an AP article by Randolph E. Schmid titled "Backpack invention generates electricity during walking". Gist is research was sponsored by the Office of Naval Research, looking for ways to reduce the need for service members to carry lots of batteries to power equipment while on duty in Afghanistan. Researchers found they would separate the backpack itself from the frame and use a system of springs to power small chargers. Right now it puts out about 7 watts. Not much, but articles says its enough to power MP3 players, PDA, night vision goggles, handheld GPS and a CSM cell phone. At the moment it adds about ten pounds to the pack, but it is thought that can be brought down to where the total 'suspended-load' backpack will only weigh a couple of pounds more than a regular one. It is thought not having to carry extra batteries will more than offset the eventual weight gain. One benefit I see it to distance trail hikers who can carry some emergency contact equipment with them.