New software called Dasher could allow computer users with disabilities or busy hands to write nearly twice as fast, more accurately and more comfortably than before and could also speed up writing on palm-tops and typing in Japanese and Chinese, its developers say.
The software lets users select letters from a screen and calculates the probability of one letter coming after another. It then presents the letters required as if contained on infinitely expanding bookshelves.

Ward, D. J. & MacKay, D. J. C. Fast hands-free writing by gaze direction. Nature, 418, 838, (2002).