Oct. 21st is the annual Celebration of Mind, in honor of Martin Gardner. Maybe you'd like to host or attend a flexagon party sometime around then, or learn about other awesome Martin Gardnery things. Here's the hexaflexagon party website: http://www.puzzles.com/hexaflexagon/
Historical Note: This video is based on a true story. Arthur H. Stone invented the Hexaflexagon and started a flexagon committee with his friends Tuckerman, Feynman, and Tukey (who all later became well-known in their respective fields). Tuckerman invented the Tuckerman Traverse, and Feynman invented Feynman Diagrams (not to be confused with Feynman Diagrams in physics, which is probably why flexagon diagrams are usually not called Feynman Diagrams anymore). The details of their interactions and dialogue, however, are my own invention.
-Feynman stuff is from the biography "Genius," by James Gleik, p. 103-104 -The story of how Gardner learned about flexagons is from "An interview with Martin Gardner" in the June/July 2005 Notices of the AMS, p. 602-611 -Other historical information, including the text and names on some of the letters, are from Gardner's original article: http://maa.org/pubs/focus/Gardner_Hex...
Thank you to the G4G-CoM committee for helping track down information, especially John Railing and Stan Isaacs for finding these sources.