Interesting Web site: Sometimes, at the Reference Desk, we get asked about tessellations. Tessellations.org is a fascinating Web site that gives many examples of tessellations by the author of the site as well as those by M.C. Escher, a major artist associated with this artform. Mathematicians, designers, graphic artists, and people who love patterns of any kind will enjoy this Web site! For additional information and designs, you will also want to have a look at Totally Tessellated. It's addictive!