United States Marines are among the best-equipped soldiers on the planet, but more gadgets mean extra batteries to haul, adding dozens of pounds on extended missions. Troops in Afghanistan recently put that hot Middle Eastern sun to use, swapping spare batteries for placemat-size solar panels on a three-week patrol. Batts were replaced with extra bullets, so the soldiers didn't get off easy, but they were also able to reduce generator usage, making a significant dent in fuel consumption. It will be several years before all soldiers charge their radios, night vision goggles, and GPS devices using the sun, but the Marine Corps hopes to cut fuel use in half by 2025, so it's only a matter of time before solar-powered gadgets have a more permanent home on the battlefield. Sha-zam!