Not an Escher, but it was cool creating it. The site also has a link to a program called TESS; not free, but pretty cool. The sample was done manually (but for now on I will stick with filters and photos;

). If any of you are a little more artistically inclined, post some of your Escher like tessellations. I would really like to see them.
http://www.tessellations.org/links.htm