Another Doug Hofstadter book! This is so cool. Ambigrams have been one of my fav "things" since I saw them in the GEB book ages ago.

FWIW, "Angels and Demons" bestseller thriller (?) has a few ambigram puzzles that the protagonist Robert Langdon solves to get to the mystery of the Rosslyn chapel (my memory may be fading here)

--x--

Thanks for this set of amazing fonts! They look amazing. Very glyph-y. And they tickle my inner geek.