The invention relates to a user-portable electronic device and in particular one which is capable of establishing transmission connection with one or more mobile electronic devices. A user-portable electronic device comprising: transmission connection circuitry arranged to establish transmission connection between the user-portable electronic device and one or more mobile electronic devices; geographic-location determining circuitry arranged to determine a geographic location of the or each mobile electronic device associated with transmission connection of the user-portable electronic device and the or each mobile electronic device; and log circuitry arranged to allow storage of a geographic-location log including at least a last-known geographic location of the or each mobile electronic device.