Sure, Mindflex was a great step forward in games, tracking your EEG waves through a headband to help you move a ball across the board. But who wants to play a game alone, right? Mattel's new MindFlex Duel is an upgraded two-player version in which you and a friend race to move the ball across the game board or through an obstacle course. It's a true battle of wits. $100 (available August 2011)
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.