I found this group of artists, Random International that created a paint roller so you can literally print on the wall. Check out the video:
Pixelroller
They also sell instant labeling tape that you just blacken out parts you don’t need to write messages. Not as cool as the pixel roller but it’s still afun idea.
Unrelated, but interesting on a technical level, this program folds a letter on screen depending on the position of your mouse.
