Many cellphones offer T9, predictive-text software that automatically completes half-typed words. The feature is a favorite among hyperefficient text-messagers, and those who are just plain lazy.
Scribe is T9 for computers. With each keystroke, the "text completion service" offers to finish the word for you – in English, Spanish, or Arabic.
Scribe won't always guess correctly, especially with unusual words. But it can be very handy with simple sentences. For example, write "To W" and the program will suggest "...hom It May Concern," potentially saving you from having to type 18 more characters.