Apfeaeiip stands for "A Place For Everything, And Everything In Its Place". In the fourth edition of The Macintosh Bible (which, by the way, was an excellent book... i don't know of any modern equivalent introductions to the Mac that do it with the same humor), Arthur Naiman asserts that the word also, coincidentally enough, spells the Fijian word for "good housekeeping".
Anyway, this supposed factoid, which I didn't know if I should take seriously or not, has been bothering me for almost two decades now, so now that we have wikipedia, I decided to finally look up "Fijian language". It turns out that it can't possibly be true: for one thing, "apfeaeiip" violates Fijian CV syllable structure: furthermore, [p] and [f] only occur in loanwords in Fijian, not in the native vocabulary.
So there, mystery solved. And Mr. Naiman... you got me.