Kumi Yamashita took shadow art to a whole 'nother level. The New York City-based artist, who is like a magician of shadows, wrote:
I sculpt shadow with light or sometimes light with shadow, but both function in essentially the same manner. I take objects and carve and place them in relation to a single light source. The complete artwork is therefore comprised of both the material (the solid objects) and the immaterial (the light or shadow).
Take a look at her gallery: Link - via Twisted Sifter (with tons of pics)
Don't miss the video profile by Takeshi Kitano's "Unbelievable":