1. A method of effecting data input with a keyboard including a first keypad having at least five keys and a second keypad having at least five keys, the method comprising: (a) with the at least ten keys of the first and second keypads, establishing at least twenty-five two-key combinations including one key from each of the first and second keypads, the two-key combinations each representing only letter characters; (b) establishing at least twenty chord combinations including multiple keys from the first keypad and multiple keys from the second keypad, the chord combinations representing only special characters and commands; (c) selecting a matrix of characters from a plurality of different matrices of characters; (d) activating one of the two-key combinations corresponding to a selected one of the characters in the selected matrix of characters to effect input of the character or activating one of the chord combinations corresponding to a selected special character or a selected command to effect input of the selected special character or activation of the selected command, respectively; and (e) repeating steps (c) and (d) until data entry is complete.