It depends on what exactly you are talking about. Yes theres a laser keyboard that shoots an image of itself onto any plain surface that can track and detect finger movement, thus giving you the ability to type on a non-existent keyboard.
Yeah, it is real...but I am not sure how well it works...seems like pressing 4 might get you "4d" or "d4"
Such systems don't have any tactile feedback, so are painful to use, slow and annoying. Nice idea, but flawed concept.
They've been around for ages, maybe not this product, but identical rivals. In any case, it's pretty obvious there's no tactile feedback, you're tapping against a desk, not real buttons. Not hard to figure out
It isn't a whole PC, but here you see the keyboard technology on something so old that it has a serial port! http://www.virtual-laser-keyboard.com/