A navigation device is programmed to be able to associate any function, belonging to a core set of functions, with a non-overlapping touch input zone that is large enough to be reliably activated using a finger. Hence, the present invention is predicated on the insight that it is possible to identify a set of core functions and to then enable all of them to be reliably selected/activated by a finger touch to a touch input zone large enough for reliable activation. This is especially advantageous for an in-car navigation device in which the core functions are those functions that are likely to be activated by a driver whilst still driving.