Geektastic: People who persist in verbalising their phone numbers incorrectly.
On that note, people that insist on making up their own phonetic alphabet and then use it wrong too. It's just "MIKE" to give "M" not "M for Mary". I'll never forget the time I was relaying something and it started with a W so I said "WHISKEY" and the other person says "W... H... I... S... K... how do you spell WHISKEY again?"