Julian Beaver's Pavement Drawings

Julian Beaver is an incredibly talented artist who does all of his on the pavement.  Below is a link to his portfolio which is comprised of a variety of his drawings.  The largest and most interesting group is the anamorphic illusions section.  Under the link you see one of many examples taken from this anamorphic section, and it is a good way to get an idea for how the illusions work and what makes them so special.  Don't forget to check out the link for many more awesome anamorphic illusions.

http://users.skynet.be/J.Beever/pave.htm