I got a friendly wakeup nudge yesterday when I realized that people have linked to my blog while misspelling my name. People have been misspelling—and mispronouncing—my name forever, so I can't imagine why I hadn't already thought of it. I keep a folder of vanity feeds—feeds based on searches for my name or sites—in my feed reader. Adding the most popular spelling error bumped it up to 55 feeds and pointed out additional references I hadn't already found.
Even celebrities have this problem (via SEW).
I don't care what you say about me. Just spell the name right.
Gene Sarazen
I imagine the monitoring companies have accounted for spelling errors in their software. If you're doing things manually or with a feed reader, consider the likely "creative" spellings of the terms you monitor, too.