Check out these pavement chalkings by Julian Beever! (Scroll down to the 3D illusions set).
I had no idea such 3D illusions were possible just by using perspective like that. (In fact, I didn't believe these were real until I saw the two photos of his globe drawing: one from the illusion perspective and the other from the side, so that you could see how it was done).
Please excuse the continued blogging of photos and links in lieu of actual, written posts. This week is rather stressful. You will be returned to your regular scheduled programme, um... eventually.
* What is it with elderly people and the phrase "on the email"? This is not normal, right? Is it some sort of extension of "on the telly", or "on the phone"?