Cognitive sensors on Computers

I had an amazing dream last night involving the desktops at Monash University library. I know it was all in my head but if it was real, it would definitely be worth the purchase. Basically, these computers react through sensors from the monitor screen. Therefore, allowing a person to move the mouse, click on objects without the need of a keyboard or mouse. Eventhough, these standard functions still remained, there was still the hands off option. With this function, even if you are a couple of metres away from the screen, if you stand directly facing the particular computer you were using, it would know it is you and pay attention to what you cognitively want to do. You can either focus strongly mentally on it, or wave your arms about, imitating a normal keyboard set in mid-air.