[UPDATE (4/14): MM creates his own ambigram.]
I was delighted to find the relatively new special edition DVD of The Princess Bride in my Easter basket this morning. I haven't even opened the box yet, but I was blown away by the cover design, specifically the ambigramatic lettering for the title. I don't think I'd ever heard the word "ambigram" until I came it across it this afternoon while trying to learn more about this kind of thing, but this is as beautifully executed as any examples I've seen. Not coincidentally, it turns out that the term "ambigram" was coined by my strange looping hero, Douglas Hofstadter. Also, not surprisingly, my mind went back to the Musical Offering, wondering if any of Bach's puzzle canons worked like this. There is the famous crab canon, which is basically a musical palindrome, but an ambigram isn't really quite the same thing since it involves an inversion as well as a retrograde.
Whoa, that's getting too technical - the real beauty of this lettering is how elegantly the artifice is concealed, so just take a look. I couldn't resist putting this little video demo together - it will save you having to flip your monitor/laptop upside down.
Meanwhile, I'm finding myself drawn in to others of Bach's canons - some of them do involve inversion, of course, although none that are strictly analogous to this ambigram. I'm working on some other experiments in realizing these canons, but this week will be quite busy, so it may be slow blogging ahead.
Other recent "strange loop" posts: Strange Loop, Swan Loop, Canon Loop.