I just wanted to thank everyone who entered our "Go Green" contest over on Instructables—and everyone else who submitted great greening ideas to the original post's comment thread. We're thrilled with the great response we've gotten, and it'll be a tough job judging all the entries. Stay tuned here for the winner's announcement and several of our favorite projects. —John Mahoney
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.