Beginning in Mac OS 10.8 Apple included a built in speech recognition tool called Dictation. Dictation allows you to speak into your computer's microphone and have your words converted to text. This nifty feature comes in handy when you don't feel like typing and in some cases you might find you can dictate faster than you can type. If you've never tried it before, you can find Dictation by going to your System Preferences and clicking on Dictation & Speech. When you dictate to your computer in addition to speaking your words clearly, you will also need to speak all your punctuation like Period, comma, and Open Quote.
I was recently chatting with a friend about this feature and they asked me if you could write something in all caps using only Dictation. I wasn't sure so I did some searching on Apple's support site and found a handy table listing all the voice commands available through Dictation. For example saying the phrase "caps on" will make the next words you speak in all caps, say "caps off" to resume normal writing mode. You can even speak emoticons like "smiley face" to get a : ) symbol.
You can view the listing of available commands by going here and clicking on Detailed list of Dictation commands: http://support.apple.com/kb/HT5449?viewlocale=en_US&locale=en_US