1. A multifunctional device comprising, within an integrated structure: a wireless signal interface; and a user input interface facilitating activating a functional mode from multiple functional modes supported by the multifunctional device, wherein activating the functional mode provides visual displays of, and access keys for, sets of input values associated with the activated functional mode, the sets of input values being segmented into multiple domain levels, the user input interface comprising three simultaneously presented, separate and distinct, key sets comprising: a set of function select keys, comprising at least two keys, for activating the functional mode from the multiple functional modes supported by the multifunctional device, the set of function select keys having associated displays for identifying the multiple functional modes, a set of domain control keys for selecting one of multiple domain levels associated with a currently selected one of the multiple functional modes, wherein each of the multiple domain levels is associated with a set of input key values, the set of domain control keys having associated displays for identifying the multiple domain levels, and a set of input keys, wherein ones of the set of input keys are associated with corresponding ones of the set of input key values for a currently selected one of the multiple domain levels, a corresponding one of the input key values being registered by the multifunctional device in response to user actuation of one of the set of input keys.