AnandTech has written an article on speech recognition:
There are a couple areas in which speech recognition can be extremely useful. For one, there are handicapped people that don't have proper control over their arms and hands, and yet they can speak easily. Given how pervasive computers have become in everyday life, flat out denying access to certain people would be unconscionable. Many businesses are finding speech recognition to be useful as well -- or more appropriately, voice recognition.