Voice interface (of the "pull the lever to speak" variety), physical buttons (e.g. T9) , physical dials (e.g. rotate to select key then press to confirm), drawing letters on a touchpad (seen it), etc.
The voice entry on my MB can be frustrating sometimes, mostly when telling it street names, but the entry knob it has is easy to use. It dials clockwise and counterclockwise, works as a four way joystick, and presses down as a button.
