Flashlight: Surefire’s military-grade torch shines more than 500 yards, even though it’s not much bigger than your hand. Its LED combines four light-emitting chips on one circuit board, instead of giving each its own electronics and case. The result is a concentrated yet efficient beam. A processor regulates power to run for 100 minutes on high, 500 on low. SureFire M3LT $450; surefire.com
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.