In terms of weird but awesome stuff found while roaming the floor of a big convention like San Diego Comic Con, Mindflex, a game that uses your own brain waves to levitate a foam ball through a board-game-sized obstacle course, tends to rank pretty high.
Mattel, who produces Mindflex, had their own booth set up separate from their main display to let people test out the game’s functionality. The ball can move up or down depending on the desired direction by wearing a headband that reads brainwaves. A dial positioned on the obstacle course is then used to move the ball from left to right.
Oh, and you also have to concentrate really hard or it’ll just look like another failed attempt at performing the Jedi mind trick (don’t act like you haven’t tried at least once in your life time.)
It doesn’t really matter what you focus on, according to the folks giving demonstration. Relaxation seems to be the key factor, but I’d suggest clearing your mind of the gorgeous booth babes strutting around in silvery outfits (lest you make other things rise).