Susan Bennett is The Best Known Unknown. Oh, you know her, you've heard her voice a million times, and now you probably have her in the palm of your hand, literally. She is Siri.Behind the groundbreaking technology of Siri, there is a real woman. Eight years ago, this voiceover actor laid down recordings for an unidentified client. She had no idea she would someday be speaking to more than 100 million people worldwide through a not-yet-invented phone that would revolutionize technology.