QWERTY Keyboard
http://en.wikipedia.org/wiki/QWERTY_Keyboard

Dvorak Keyboard
http://en.wikipedia.org/wiki/Dvorak_keyboard

Maltron Keyboard
http://en.wikipedia.org/wiki/Maltron_keyboard

Chord Keyboard
http://en.wikipedia.org/wiki/Chord_keyboard

T9 (Predictive Text Entry for Mobile Phone)
http://en.wikipedia.org/wiki/T9_(predictive_text)

Graffiti (Palm OS) Handwriting Recognition System
http://en.wikipedia.org/wiki/Graffiti_(Palm_OS)

Speech Recognition
http://en.wikipedia.org/wiki/Speech_recognition
IBM ViaVoice http://en.wikipedia.org/wiki/IBM_ViaVoice