. it was always "P as in Psychology" or "M as in Mnemonic". Periodically I'd get a chuckle out of a customer,
but more often, my mind conjured up images of people with blank stares holding the receiver up to their addled heads.

Ah, FB, I love it! I've done the same, though not always with something like "gnostic" for "G." Just using a word that's not used in everyday parlance works just as well. Heck, "parlance" is a good example itself. Something like "P" as in parataxis - that'll shake 'em up!