Today in license plates: PIB4159, seen on a Porsche driving south on Georgia 400 just north of I-285, when I was coming home from work. Georgia license plates are three letters followed by four numbers by default, so this isn’t a vanity plate. At least I don’t think it is. But a B does kind of look like a 3 and a 1 together… unfortunately in the wrong order to make this is a six-digit approximation of pi.
(If they’d let me, I’d get CAB1729. People would just think it was a normal plate.). I’ve always thought that it’s not quite so impressive that Ramanujan noticed that 1729 is the sum of two cubes in two distinct ways – it’s 1000 + 729 or 1728 + 1, and both of those are easy to see by eye.
For more, you should read Knuth on mathematical vanity plates.