A human interface configured to optimize a biomechanical effect of a human user's opposing thumb and fingers by including, on one surface, one or more software configurable input elements manipulatable by a user's thumb(s) or a stylus, and, on another surface, one or more software configurable selection elements manipulatable by a user's finger(s). A selection element may be a pressure sensor pad configurable to represent delineated active areas that are mapped to one or more input functions. Shape changing media may be provided to permit a user to tactilely discriminate between delineated active areas. Tactile feedback may be provided to a user through palpable detents, vibratory or force producing units. Inputting data may include mapping each selection element to a shift function, mapping each input element to text functions, and using the selection elements to shift between text functions associated with an input element to input a desired text function.