Dictation software is typically expensive, but if you're looking for a quick, free, and cross-platform solution, Remote Dictate turns your iPhone 4S into a dictation microphone for use in any program.
After downloading the iOS app, you also need to install the company's free Mobile Mouse server software for Mac, Windows or Linux. From there, the set up is as easy as loading up Mobile Mouse on your computer and opening up the Remote Dictate app on your iPhone 4S.
The app will automatically find your computer and a quick tab on the microphone will start the dictation. You will need to add your favourite text editor software to Mobile Mouse, but other than that, the process is straightforward. Remote Dictate is currently a free download on the iTunes App Store.