Yesterday’s “All Things Considered” featured a story about Tremont Electric’s Personal Energy Generator (PEG). It’s a device that captures the energy from walking and uses it to charge portable electronic devices.

To learn more, listen to NPR’s story or visit Tremont Electric online.

But remember that, as described in The Human-Powered Home, energy passively harvested from walking or other routine activities does take its toll. Hours of charging your music player with Tremont’s PEG as you walk will make you a little more tired than walking without charging. This is what the U.S. military learned from its experiments with the heel-strike generator and why they scrapped that project in favor of hand-cranked generators to charge portable communications devices.