http://gprime.net/images/sidewalkchalkguy/ [ame="http://www.youtube.com/watch?v=C3invCYxOMg&feature=related"]YouTube - Amazing Sidewalk 3D Art[/ame][ame="http://www.youtube.com/watch?v=9tr5kQ5ZC90&feature=related"]YouTube - Optical illusions and 3d chalk drawings[/ame]