A hand held mobile telephone (1) is disclosed comprising a front face (3) having a plurality of openings therein, and a plurality of keys (7 13) each having an upper surface bounded by side walls. Each key (7 13) protrudes from one of the plurality of openings to provide its upper surface for tactile actuation by a user. The telephone further comprises an underlying switching element and means for coupling the tactile actuation of the upper surface by a user to the switching element. One of said plurality of keys has a vertex, in the boundary of its upper surface, indicative of the location for tactile actuation.