Wordplay - By John Langdon

John Langdon, the inspiration (at least, in part) for fictional Harvard professor Robert Langdon in Angels and Demons) wrote Wordplay which was updated in November of 2005. 

The following is Amazon's description of it:

This lovely updated edition of the classic collection of ambigrams features a section of full-color ambigrams and dozens of stunning, mind-bending examples of this cryptic art form. Each strikingly beautiful and arresting illustration is accompanied by a short essay—sometimes serious, sometimes witty—to delight your brain as much as your eyes. Taken together, the art and the essays show how the very shape of letters can change our idea of words and their meanings.

Click on the cover for a closer view.

Credits

Image of book cover, online courtesy Wikimedia Commons. 

Details about updated edition of Wordplay:

Paperback:   224 pages

Publisher:     Broadway (November 8, 2005)

Language:    English

ISBN-10: 0767920759

ISBN-13: 978-0767920759