Leave It To Beever
An English artist named Julian Beever has been making pavement drawings for over ten years. His work has graced the streets and sidewalks of Australia, Belgium, France, Germany, the Netherlands, the UK, and the USA. His most famous works are "[a]namorphic illusions drawn in a special distortion in order to create an impression of three dimensions when seen from one particular viewpoint."
To give an example, this shot of a "swimming pool" on the streets of Glasgow, Scotland, looks well enough at the proper angle:
Now then, here is how it looks from the other end:
As one can see, "[t]hese drawings only work from one viewpoint otherwise the image appears strangely distorted."
Another example can be seen in this series of five drawings used by White's Electronics of Inverness in Treasure Hunting magazine.
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If you want your own sidewalk done, Julian can be reached via e-mail at julian dot beever at belgacom dot net. In any case, I suppose the question of whether this constitutes good art depends on your... point of view.