Interesting optical illusion

Zack Lynch posted this fabulous optical illusion called rotating snakes by A Kitaoka. [Zack had posted it as a Microsoft Word document, which I had converted to HTML/PNG in the interest of portable standards, but now it's available as a GIF on the creator's web site]

The image is Copyright A. Kitoaka 2003 (September 2, 2003)
Mark Moraes Valid HTML 4.01 Support Browser Diversity! This work is licensed under a Creative Commons License.