Stumbled upon

http://www.endofworld.net/ (long load - but worth it! check the other ones out while it's loading or STFU already!)

http://www.zefrank.com/scribbler/

http://www.400monkeys.com/God/

http://www.aseltine.com/rhee/

http://dura.cell.free.fr/home/swf/arms12.swf

http://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception/colourPerception.html

http://www.tashian.com/multibabel/

http://www.gauravjalan.com/entertainment/pictures/strange/illusion/FrameSet.htm

http://www.cannabis.net/weblife.html

http://allthingsflash.com/files/games/curveball.swf

http://web.mit.edu/afs/athena.mit.edu/user/d/r/dryfoo/www/Funny-pages/handy-latin.html

http://www.typenow.net/themed.htm (for the graphic designers)

http://www.ritsumei.ac.jp/~akitaoka/rotate-e.html