o2 Creative Solutions is an "experience design firm" that seeks to combine design, communications and technology. Up above is their Etch-a-Sketch-inspired Sketch-3D tool:

Sketch-3D is an interactive, integrated software/hardware system that enables users to create their own anaglyphic 3D drawings. By using a ubiquitous interface metaphor (the "Etch-a-Sketch"), Sketch-3D allows anyone to participate in generating stereoscopic imagery in a way that is simple and engaging. In addition to the personal experience, Sketch-3D can be scaled to work with any output device from large scale projection to plasma displays to an integrated LCD. This versatility allows for Sketch-3D to be tailored to fit a wide array of installation environments.

No word on how to erase it, but we're guessing you have to get two people to rip it off the wall and shake it vigorously.

via diskurdisko