Rob Nero, one of the MA in Interaction Design at the School of Arts and Communication, Malmö University, had the idea of using laser beams and IR sensors to develop a flat multitouch surface. It has some drawbacks, but it is 100% Arduino made, using breadboards, resistors, IR transistors, 4051 multiplex ICs, one Arduino Mini and the USB-Serial converter … 100% genuine prototype.

He is making a great collection of videos showing the functionality of it. Here one example, visit his Vimeo profile for more!