The keyboard has served moderately well as an input device. For alphabet centric languages the number of keys in a QWERTY keyboard are not a limitation. There are mechanical limitations, in that only one key is on a key - common phrase or word construction keyboards are rare, and of course there is a learning curve associated with the keyboard - the QWERTY layout, is, after all, designed to slow down keyboard entry and dates back from the time of mechanical keys striking each other on the way to the page.
Where modern keyboards are not as useful is where a medical condition inhibits use. Chief amongst these is arthritis where joint deterioration makes it painful or impossible for people to use the keyboard. A further problem is where an individuals sight is impaired.
In cases like this a decent bit of voice recognition software can be very helpful. The most popular of this ilk we could find is Dragon Dictate. As the name suggests the software is basically used with the aid of a headset in the traditional dictation mode. There are however some differences. Firstly, unlike human dictation, a computer must be trained to recognise the users voice. Without this training accuracy is limited.
Training voice recognition software is monotinous to say the least, and involves reading defined phrases repeatedly. The pay off comes later as only through standardisation is the software able to recognize the characteristics of your particular voice.
In use, it should be understood that not all software is designed for voice recognition software. Word processing software is the most suited, with speeds approaching 40 odd words a minute in my use (everyone will achieve different levels of success).
Voice recognition software is not well suited to non-standard applications. I found none of the available software to be particularly useful with Excel and utterly useless with database software. And you can forget about working in DOS command lines.
Still if you must use voice recognition software then it beats nothing. For me, I would still prefer to use the keyboard as it is a far more flexible input device. Whilst my keyboard skills are prone to error these are far less than the errors which are created when I use voice recognition software.
If you are going to use voice recognition software, even a good package like Dragon Dictate, it is highly recommended that you purchase a headset with a microphone attached. Using a keyboard a little bit and the voice recognition software together can become efficient, but you do need to keep your hands free and a headset achieves this very well.
