This is not possible . . . but it is.
i received a gecko and fly mail today . . . about this great chinese man named Shigeo Fukuda. who created the following optical illusions :
This is a weird one. That pile of garbageis aligned in such a manner that its shadow is that of a motorbike :P.

This one’s even weirder. That odd assortment of piano parts casts an image of an actual piano when seen in a mirror !!!!!!
This is tight !!
well, one more thing :
If you love optical illusions, then you’ll love this color optical illusion by Prof. Edward Adelson .

awesome!
and the checker shadow too.
You have a nice blog!