Julian Beever is a chalk artist in the U.K. who specializes in three dimensional optical illusions. They are fantastic and very cool works of art. I had to do a double-take on some of his work as it was hard to believe the drawing was not real. He has a website full of his other works, so go on over there and check them out. They are way cool eyecandy! You can see his entire portfolio by clicking here. Enjoy!