I have been here all week silently following along (usually late at night!). You were interested in testing the links to other sites in your Historical and Geographical Connections in the Tessellations lesson. . . I had trouble linking to the "Images of the Alhambra". The first message that I got indicated that there might be a problem with the address (www.nyu.edu). The second message indicated that the server might be down, so I'm not sure what was going on.
I enjoyed demonstrating your tessellation technique with HyperStudio at the Indiana Summer Institute of Technology last week. I am doing another workshop next week for high school teachers which focuses on assessment. One of the topics we are discussing is tessellations, so I plan to take my computer with me to demonstrate your method again. I can't wait to try it out with my students next year.
I am a quilter, so when I talk about tessellations in class, I bring in quilts and pictures of quilts to show examples of tessellating squares, triangles and hexagons. There is even a quilting book entitled "Tessellations" (by Jackie Robinson) which illustrates some "Escher-type" tessellations.