One day it will be possible to control computers with your brainwaves without the need for speech, keyboard or stylus. This article describes some of the advancements being made allowing brain waves to control a computer in such a fashion that many with strokes and other debilitating conditions can communicate effectively.
The technology does not allow rapid conversation yet but it seems that it will get better and better over time. Certainly the military will be interested in this technology as well. Perhaps their interest will speed up adoption of such technology.