[mtmail]

On my list would be the artist Prince, who changed his name to an unpronounceable symbol, which was (and still is) not part of Unicode so newspapers weren't able to print it. We ended up with "The Artist Formerly Known as Prince" for 7 years. He changed his name back. Maybe there's hope for Twitter, too.

[marssaxman]

That was kind of a genius move, though, despite its weirdness: performing under a different name gave him leverage in his contract battle with Warner Brothers, but using a name which was neither pronounceable nor printable meant that everyone (effectively) kept calling him "Prince" anyway.