I am dictating this post using MacSpeech Dictate. It is amazing and much better than I expected at understanding what you’re saying. In addition to dictation it also allows you to control your computer, with commands such as “open mail” and “put this computer to sleep”.
When you are controlling your computer you have to be careful to use the correct language and it does take a bit of getting used to but it’s quite easy. There is an on-screen list of commands to refer to and most of them are fairly intuitive.
As far as I can tell MacSpeech Dictate seems to work in all applications. I have used it this morning in TextMate to write an XML document. Speaking “open angle bracket” is almost as easy as typing angle bracket. And long sections of text are obviously much easier to speak.
MacSpeech Dictate is able to detect commands during spoken text. Adding punctuation is easy, to add a full stop just say “full stop”. Correcting mistakes can be a little painful but can be done. Deleting a single word is done by saying “forget word” and deleting the last chunk of text that you dictated can be done by saying “forget that”.
It is really good in iChat. Being able to speak is exactly what you want when writing a chat message.
However, don’t forget to read what you wrote because it can make mistakes!