M.C. Escher (http://www.mcescher.com/)
Escher for Real (http://www.cs.technion.ac.il/~gershon/EscherForReal/)
Beyond Escher for Real (http://www.cs.technion.ac.il/~gershon/BeyondEscherForReal/)
Escher on video (http://video.google.com/videosearch?hl=en&q=escher&um=1&sa=N&tab=wv)
NYC Photo Gallery (http://www.nyc-photo-gallery.com/Poster_Escher.htm)
Google Images (http://images.google.com/images?um=1&tab=wi&hl=en&q=escher)
Lego Escher (http://images.google.com/images?hl=en&q=%22lego+escher%22&um=1&sa=N&tab=wi)
(http://www.cs.colostate.edu/~rogersma/xkcd/escher_wristband.jpg)