Definitely the weirdest in-production musical instrument I've seen for a while is the ElectroKraft Axe Synth. It seems to be a finger-controlled theremin, with really strange styling, even for a theremin. You really need to watch the video to get the hang of it. The Axe Synth was invented by guitar-maker and poet Anthony Amendolare. He lives near Long Beach, New York, and started out building traditional Spanish guitars and hand-winding pickups. Something must have happened in his life, because now he's totally into freaky electronic stuff. The Axe Synth is the only thing off the drawing board, but I'm looking forward to the Photon Synth and Sonar Synth. You can buy an Axe Synth from Anthony for $549, and if you're in any doubt, there's a totally impartial review here on Sonic State.