(via) Okay, this is damned nifty. Neato, even. Ostensibly the origin of punctuation marks, reprinted from Uncle John’s Supremely Satisfying Bathroom Reader.

Origin: When early scholars wrote in Latin, they would place the word questio - meaning "question" - at the end of a sentence to indicate a query. To conserve valuable space, writing it was soon shortened to qo, which caused another problem - readers might mistake it for the ending of a word. So they squashed the letters into a symbol: a lowercased q on top of an o. Over time the o shrank to a dot and the q to a squiggle, giving us our current question mark.

More interesting stuff in the link.