Among all the technologies designed by Spaceman Technologies, the one I found the most curious is this "Ultra-fast virtual air hockey":

"In 2001 Spaceman Technologies developed a large table-top virtual air-hockey platform for up to four players. Incorporating a proprietory ultra-fast velocity-sensitive multitouch touchscreen and a 500+ frames per second high-resolution LED display screen. The touchscreen is capable of tracking players' fast sweeping hand movements. A hand's velocity and point of contact with the virtual 'puck' can therefore be determined. This velocity and position data is factored into the physics of the simulation so that the puck responds in a realistic manner to contact with the players' hands. The high frame rate of the screen ensures that the puck image does not flicker even when moving at high speed across the table - giving an 'analogue' feel to the game."

Why? because it's a sort of hybridization of real and digital artifacts which seems playful. And it's spot on a talk I am working on for next week (need examples to show).