Slicing the Menger Cube - Neat!

http://www.scientificamerican.com/article.cfm?id=mathematical-impressions-the-surprising-menger-sponge-slice

Hexaflexagon Safety :)

http://www.youtube.com/watch?v=AmN0YyaTD60&feature=em-uploademail-new

More Hexaflexagons

http://www.youtube.com/watch?v=paQ10POrZh8&feature=em-uploademail-new
Vihart video Hexaflexagons 2

Hexaflexagon celebration Website:  http://www.puzzles.com/hexaflexagon/

Previous Years:  http://www.puzzles.com/hexaflexagon/aroundtheworld.html

Martin Gardner's post on Hexaflexagons 1956:  http://www.puzzles.com/hexaflexagon/aroundtheworld.html

Vihart Hexaflexagons

http://www.youtube.com/watch?v=VIVIegSt81k&feature=em-uploademail-new

Nice Tessellation - angry bull and bear

http://www.moillusions.com/2012/09/spot-the-opportunity-illusion-poster.html