An electromagnetic pulse (EMP) may knock out all electronics within a certain range, but a Faraday cage can shield against electrostatic charges and radiation. That's the idea behind this anti-EMP bag. "My HAM radio was saved by being wrapped in a Faraday cage!" your paranoid giftee will say after the apocalypse, as he treks through the ruined wasteland. "That guy who got it for me: What a thoughtful friend he is! Er, was." $27, Amazon
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.