According to my mother (who is a kind of mythomaniac, so who knows if it's true), an uncle of mine (her brother) invented the yellow "smile face" button. He didn't get anything from it, though, or not much, because he worked for some mining equipment company or something (I don't remember that part of it), and was an inventor, and anything he invented at that time was considered the property of the company.
If it's true, he's not really famous, but the inventor of something famous (so has a kind of "hidden fame").