Procedure for use of applications in a mobile telephone as well as a mobile telephone

The invention relates to a mobile radio communication unit, comprising a controller (MCU) and at least one storage device (6). The at least one storage device stores at least one application program and identification information, wherein the identification information identifies a user of said mobile radio communication unit. And the mobile radio communication unit comprises an interface (7,23,8) coupled to the controller (MCU), the interface being for mechanically and electrically coupling to the at least one storage device. The at least one storage device is attachable to the interface (7), wherein while the interface is mechanically and electrically coupled to the at least one storage device, the controller is electrically coupled to the at least one storage device, and the application program is adapted to send messages to another application via the interface.