Modular mobile communication system

An expansion card adapted to be fitted into a connector socket in a portable host device, said portable device having a control unit and a cellular telephone unit connected to said control unit, said expansion card comprising:

• a housing having a shape which enables said expansion card to fit into said socket, said socket adapted to receive the expansion card, wherein, in the received position, the expansion card is connected to said control unit and a surface of said housing of said expansion card cooperates with a surface of said portable device to define an exterior surface for said portable device;
• elements for realizing an additional function for said portable device;
• and
• a memory element for storing software required for controlling said elements, wherein said software is adapted for execution at least via the user interface of the portable device.

A portable device for personal communication having a cellular telephone unit and at least one expansion card connector socket for connecting expansion cards to the device for adding an additional function to the functions of the device;

• wherein said socket is adapted to receive the expansion card in a position, such that the surface of the expansion card cooperates with a surface of the host device to define an exterior surface for the device;
• and
• further wherein the device is arranged to read identification information from at least one of said expansion cards when connected to the expansion card connector socket;
• the device is arranged to determine whether said identification information indicates that the expansion card comprises the program needed for controlling the expansion card, to control the functions of the expansion card by means of said program, wherein said program is adapted for execution at least via the user interface of the host device.