Links Dr. Enger likes-

Tessellations
If you and your students are interested in tessellations, you might find ideas that you can use or modify at these Web sites.

What is a tessellation? (Math Forum) http://mathforum.org/sum95/suzanne/whattess.html
SHODOR (Computational Sciences) http://www.shodor.org/
Online interactive tessellation tool http://www.shodor.org/interactivate/activities/Tessellate/
A tessellation App is available from iTunes- ($0.99) Math Flyer (iPhone & iPad).
Online NCTM Tessellation Creator http://illuminations.nctm.org/ActivityDetail.aspx?id=202
Tessellations http://www.tessellations.com/
Totally Tessellated (Projects for Students by Students) http://library.thinkquest.org/16661/
Teaching with Tessellations http://www2.gvsu.edu/~oxfordj/teach.html
Totally Tessellated (Templates) http://library.thinkquest.org/16661/templates/index.html
You Tube Videos (Just a Sample)
Tessellations: How to Create Them (Preview) http://www.youtube.com/watch?v=iVXLU3SYCBw
How to Make an Escher-esque Tessellation http://www.youtube.com/watch?v=212XC1zfxXY&feature=related
Escher Style http://www.youtube.com/watch?v=h2AWKgU0cN4&feature=related
Anatomy of an Escher Flying Horse http://www.youtube.com/watch?v=NYGIhZ_HWfg&feature=related
Anatomy of an Escher Lizard http://www.youtube.com/watch?NR=1&v=T6L6bE_bTMo&feature=endscreen