Richard Gregory was a much loved and hugely influential perceptual psychologist who passed away earlier this year.
Tom just alerted me to a wonderfully appropriate visual palindrome on his page of remembrance where his name reads perfectly well when either the ‘right way up’ on when ‘turned on its head’.
If you can’t see it or don’t believe it, go to the site and click the corner to see the image rotate.
A small but charming tribute to a man who used visual illusions to demystify perception.
Link to Richard Gregory tribute site.
Mind Hacks 
Ambigram, not palindrome.
What John said.