A portable electronic device (10, 10A, 10B) comprising: a memory for storing movement pattern data representing a first pattern of relative movement between the portable electronic device and an imaging surface; a motion sensor for sensing relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface and for generating a first set of motion data representing a second pattern of relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; and a controller for comparing the first set of motion data to the stored movement pattern data, the controller configured to identify a user of the portable electronic device (10, 10A, 10B) based on the comparison of the first set of motion data to the stored movement pattern data; the portable electronic device (10, 10A, 10B) further comprising: a menu display having a plurality of menu items, and a menu item pointer movable by the user to highlight particular menu items; the motion sensor being configured to generate a second_set of movement data indicating a first relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the motion sensor being configured to generate a third set of movement data indicating a second relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the controller being configured to move the menu item pointer based on the second set of movement data to highlight a first menu item; the controller being configured to select the first menu item based on the third set of movement data; and wherein the controller is configured to take into account a velocity, an acceleration, or a repetition of a motion of the imaging surface relative to the motion sensor for enabling the controller to cause a specific action wherein the controller is configured to enable operation of the portable electronic device after the first set of motion data matches the stored movement data. a memory for storing movement pattern data representing a first pattern of relative movement between the portable electronic device and an imaging surface; a motion sensor for sensing relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface and for generating a first set of motion data representing a second pattern of relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; and a controller for comparing the first set of motion data to the stored movement pattern data, the controller configured to identify a user of the portable electronic device (10, 10A, 10B) based on the comparison of the first set of motion data to the stored movement pattern data; the portable electronic device (10, 10A, 10B) further comprising: a menu display having a plurality of menu items, and a menu item pointer movable by the user to highlight particular menu items; the motion sensor being configured to generate a second_set of movement data indicating a first relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the motion sensor being configured to generate a third set of movement data indicating a second relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the controller being configured to move the menu item pointer based on the second set of movement data to highlight a first menu item; the controller being configured to select the first menu item based on the third set of movement data; and wherein the controller is configured to take into account a velocity, an acceleration, or a repetition of a motion of the imaging surface relative to the motion sensor for enabling the controller to cause a specific action wherein the controller is configured to enable operation of the portable electronic device after the first set of motion data matches the stored movement data. a menu display having a plurality of menu items, and a menu item pointer movable by the user to highlight particular menu items; the motion sensor being configured to generate a second_set of movement data indicating a first relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the motion sensor being configured to generate a third set of movement data indicating a second relative movement between the portable electronic device (10, 10A, 10B) and the imaging surface; the controller being configured to move the menu item pointer based on the second set of movement data to highlight a first menu item; the controller being configured to select the first menu item based on the third set of movement data; and wherein the controller is configured to take into account a velocity, an acceleration, or a repetition of a motion of the imaging surface relative to the motion sensor for enabling the controller to cause a specific action wherein the controller is configured to enable operation of the portable electronic device after the first set of motion data matches the stored movement data.