AirBar is a slim USB peripheral that attaches to the bezel of a laptop and adds a touchscreen functionality to a display. Once you’ve plugged it in, it blankets a display with “an invisible light field”.

It doesn’t require any special software to work, as long as it’s connected to a Windows 7, 8, or 10 machine — or a Chromebook — it’ll work. Support for Macs is coming.

Also it doesn’t matter what you touch the screen with. You don’t have to use a special stylus, it even senses a touch while wearing thick work gloves. Anything that breaks up the light field will do the touch.
 

It’s a pretty slick device, and pre-ordering one will only set you back $49. Unfortunatelly, you can’t attach it to any display and turn it into a touchscreen, because at the moment it only works with 15.6-inch laptops.