Heh, was about to post this one myself. My buddy got in big trouble in the high school computer lab making this typo. I wonder what percentage of domains in the late 90's were simply "adult" sites trying to capture traffic via typos. It certainly felt like a lot.
Then there was expertsexchange.com, which was always bound to disappoint one of two demographics.
Heh, like the msexchange manager icon on your microsoft exchange server... :D