It’s MUCH faster than typing out a message, surprisingly accurate and will copy the text to the clipboard for use in whatever other app.  The downsides?  Voice recognition is done on their servers, meaning it uses bandwidth, but only takes a few seconds and they upload the names from your address book (but not any other data) so it will recognise any names of people you speak.  If you have a US iTunes store account it’s free.

The review is here: iPhone J.D..