This installation was commisioned by Ernst & Young for the Union Square Citibank branch. It is a custom designed and built, freestanding wall with conductive traces laid down on oversized Lego baseplates. Oversided Lego bricks were designed with connected LEDs and arranged in a way that when placed on the board in any orientation, the LED leads would make contact with the conductive traces and light one of the LEDs.
Check out my 3D Models page to see SketchUp rederings of this project