The basic hypertrochoid equation from Mathworld

Fake Battlestar Galatica Money

Sothis Horus Guilloche Dial on Strap

György Kepes, Hand and Geometry, 1939

Spirograph Toys launched in 1965

Title Sequence for Alfred Hitchcock’s Vertigo, Art Directed by Saul Bass

Cover for Cybernetic Serendipity: the Computer and the Arts, Frederick Praegaer, 1969. This book describes the seminal exhibition at the ICA, London, curated by Jasia Reichardt in 1968. (Wikipedia entry)