For Pi day, let me plug David Blatner’s The Joy of Pi, a short tome of fun facts about pi, whose main advantage is that it cites me, saying something along the lines of “Sure, memorizing digits of pi isn’t useful, but saying that math has to be useful is like saying that the English language is only good for ordering pizza.”

What was that all about? Back in 1996 [UPDATE: actually 1994, but I publicized it in 1996], I and some friends made up a little mnemonic paragraph to remember the value of pi to 167 digits. (There may be a slight error in there; I no longer remember.) That item was picked up in a number of places, including The Scientist and Ivars Peterson’s MathTrek column.

Otherwise, I’ve never profited from this invention, so I share it with you now for free lest it be lost forever. Of course, there are a great many pi mnemonics out there, some much longer than 167 digits; see, e.g., Poe, E.: Near a Raven (740 digits), which isn’t even the longest.

In other news, if you type in “pi” in the iTunes store, you find a number of interesting songs called “Pi”, some of which sound interesting. Downloads of the day?

UPDATE: I forgot to mention Nobel laureate Wislawa Szymborska’s poem about pi. Here it is in Polish; here’s one English translation, and here’s another.