The days of rummaging for your cellphone may be over. Bluetooth-enabled timepieces now pull all your phone alerts right to your wrist. Eventually, these watches will communicate directly with the Web and serve as mobile hotspots on their own.
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.