14. A data entry device having at least one output unit and a virtual input unit having a plurality of virtual key regions configured to: associate a group of symbols with each of a single virtual key region from the plurality of virtual key regions; assign to each finger of a user having a group of fingers a single symbol from the group of symbols; an optical sensor positioned remote from the virtual key region to identify a virtual key region about to be actuated by the user to define a candidate key region; identify and detect with the optical sensor a most probable finger that is about to actuate the candidate key region; determine the most probable symbol based on the identity of the most probable finger and the candidate key region; display via the output unit the group of symbols associated with the candidate key region; apply a visually-perceptible emphasis to the most probable symbol to differentiate it from the display of the other symbols in the group of symbols; display via the output unit a visually-perceptible representation of the group of fingers; and apply a visually-perceptible emphasis to the most probable finger to differentiate it from other fingers in the group of fingers.
17. The device of claim 14 wherein the visually-perceptible emphasis is selected from the group consisting of: bold font, italics font, flashing text, shaded text, displaying the most probable symbol in a font different from the other symbols in the group, and displaying the most probable symbol while the other symbols of the group are not displayed.