A switch arrangement is disclosed. The arrangement comprises a number of switches arranged on a substrate, each switch having a resiliently deformable conductive dome for making an electrical connection with a corresponding contact on the substrate; and a number of signal lines for connection to a microprocessor for signalling an operation of a switch. The switches are arranged such that operation of any given switch creates a unique electrical connection between two of the signal lines and each of the signal lines is electrically connected to a conductive surface of a respective dome. Also disclosed is a cover for a portable electronic apparatus, having a number of user operable keys. The keys are connectable to a microprocessor in the apparatus via electrical connections made using the conductive domes.