The original ambigram generator on the Internet, since 1995!

The first online store devoted 100% to Ambigram-related merchandise.

A well-rendered last name, and some samples and basic information about Ambigrams as well.

Wendy explains how she developed her tiled background -- not exactly an ambigram, but very Escher-esque!

Isaac Asimov called him The Escher of the Alphabet, which sums it up for me. Scotts book, Inversions, got me started (along with thousands of others, Im sure). Includes links to other ambigrams on the web, as well as an original Inversion of the week.

Douglas Hofstadter called him a marvelous creator and a consummate artist. Langdons book Wordplay gives elegant examples and goes into the philosophical background of his ambigrams. His website provides an opening chapter that describes the process of developing an ambigram as well as a dissertation on symmetry.