This video's [Google Video] being passed around the Internet today. It's a video of Microsoft's attempt at speech recognition in Windows Vista (Microsoft's future OS) during a demo for press and investors. Apparently, Microsoft didn't do a great job setting up their live demo.
Basically, Microsoft's representative tried to speak 'Dear Mom,' to the computer, but the computer typed 'Dear Aunt,' instead. Once the representative tried to replace or delete the text, the computer took a little time to think, then output: "Dear aunt, let's set so double the killer delete select all."
Perhaps there's a reason why Apple has not endeavored to make a full 'speech typing' utility for their system. Apple has probably realized by now that the built-in speech recognition they currently employ in OSX is plenty adequate and very robust for most users, and that they don't need to delve into markets where they will waste tons of time for not-so-great return on investment.