I think my favorite typo is taht of the word 'that'. Because when you typo it, you're really just spelling it backwards.

When I used to chat with a girl who would typo EVERYTHING, I almost got accustomed to typing 'adn' because she would all the time.

We were both members of a "Typosian" royalty at our harry potter rpg. We had the Typo Queen, typo Evil Queen (aforementioned girl), assorted princes and consorts, dukes and duchesses (yours truly, a cousin of someone or something xD). We made little aliases in mIRC to show off our Typos (the country) pride. One of the guys made a little anthem as well xD

Typos tiem?