It looks like you're new here. If you want to get involved, click one of these buttons!
If you are extensively using Siri to dictate emails, text messages etc. on your iPhone 4S then you're probably missing it while typing things on your computer.
Folks at Avatron who have brought us apps like Air Sharing, which turns your iPhone into a portable drive have just released an app called Air Dictate that will allow you to dictate on your Mac using Siri.