LAS VEGAS — Put this tubular object in your backpack, and you can generate juice for your cellphone — just by walking around.

The nPower PEG (short for “personal energy generator”) contains a weight, a spring, some inductive coils and a battery. Put it in your pocket or your backpack, and it wiggles around with your body’s natural movements. As the internal weight moves, it generates electricity in the coils, which gradually charges up the battery. You can then transfer that power to your phone or iPod via a mini USB port and an adapter cable.

It’s a brilliant idea, and anyone who has ever watched their battery indicator dwindle to nothing will surely love the idea of getting energy from nothing more than walking and fidgeting. However, for power-hungry smartphones, you’ll only get about a minute of talk time for every 15 to 30 minutes of walking, the company says. That’s hardly enough to keep your phone alive all day.

Full story: Turn Your Body’s Motion Into Power for Your Phone | Gadget Lab |