Make your own multitouch projected table

Multitouch, it's all you bloody hear about these days.  If another person stops me in the street or blocks my car in just to shout "Apple have invented a multitouch cellphone!" into my face, I'll scream.  Okay, so a huge company spent over two years developing a compact screen that could respond to more than one finger jabbing at it.  So what?  What's far more impressive to my mind is this four-day project to make a multitouch table:


It all relies on the wonderfully-named Frustrated Total Internal Reflection (FTIR), whereby the path of LED light internally reflected between a sheet of acrylic and a diffuser is changed by the touch of a finger or other object placed against the top acrylic.  That's then picked up by a computer, and a projector mounted underneath the table displays the appropriate response.

I'm really tempted to make one of these myself, it looks like great fun.  I could also use it to club to death anyone who mentioned a certain Apple cellphone's innovative interface...

Multitouch Table Experiment [via MAKE]