Enjoy Cliff Pickover's Mind-Bending Puzzles and the ever-popular (and newly repackaged) Kaleidocycles. Also, don't miss crosswords and more from the New York Times. Optical Illusions: A 2009 Sketchbook Calendar for the Visually Intrigued $13.99 Mind-Bending Puzzles: A 365-Day Calendar for 2009 $12.99 M.C. Escher Kaleidocycles Boxed Gift $24.95 How to Understand, Enjoy, and Draw Optical Illusions $14.95 Who Am I? A Name Game of Popular Music Stars Knowledge Cards $9.95 Can You Name Them All? A Quiz Deck on Everything from the Three Musketeers to the Seven Seas Knowledge Cards $9.95 Mind-Bending Puzzles: Famous-Name Anagrams Knowledge Cards Cliff Pickover $9.95 Mind-Bending Puzzles: Cryptorunes Knowledge Cards Cliff Pickover $9.95 Mathematical Games Knowledge Cards $9.95 Scientific American Mathematical Games, Volume 2 Knowledge Cards $9.95 Scientific American Head Games: 48 Confounding Word & Math Puzzles Knowledge Cards $9.95 What Did They Do? Big Accomplishments of Not-So-Well-Known People Knowledge Cards $9.95 All of our pictures enlarge; click on any picture for a closer look. Text & images protected by copyright. Sign Up for Our Monthly E-mail Newsletter Private list, unsubscribe any time. Home | Customer Service Center | Ordering Information