An input device (500; 600; 700; 800) comprising: a position sensor; and a processor configured to: switch between operation modes as a function of orientation measurements detected by the position sensor; enter a three-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a first orientation, and enter a two-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a second orientation, wherein the 2D input mode is configured to provide 2D position data to a connected computer system, and wherein the 3D input mode is configured to provide 3D position data to the connected computer system; characterised in that the input device (500; 600; 700; 800) further comprises: a first set of buttons positioned to be accessible by one or more fingers on a hand of a user while the hand of the user is resting upon the input device, when the user is operating the input device in the 2D input mode; a second set of buttons positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode; and a touch pad positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode. a position sensor; and a processor configured to: switch between operation modes as a function of orientation measurements detected by the position sensor; enter a three-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a first orientation, and enter a two-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a second orientation, wherein the 2D input mode is configured to provide 2D position data to a connected computer system, and wherein the 3D input mode is configured to provide 3D position data to the connected computer system; characterised in that the input device (500; 600; 700; 800) further comprises: a first set of buttons positioned to be accessible by one or more fingers on a hand of a user while the hand of the user is resting upon the input device, when the user is operating the input device in the 2D input mode; a second set of buttons positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode; and a touch pad positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode. switch between operation modes as a function of orientation measurements detected by the position sensor; enter a three-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a first orientation, and enter a two-dimensional input mode when the processor detects that the input device (500; 600; 700; 800) is in a second orientation, wherein the 2D input mode is configured to provide 2D position data to a connected computer system, and wherein the 3D input mode is configured to provide 3D position data to the connected computer system; characterised in that the input device (500; 600; 700; 800) further comprises: a first set of buttons positioned to be accessible by one or more fingers on a hand of a user while the hand of the user is resting upon the input device, when the user is operating the input device in the 2D input mode; a second set of buttons positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode; and a touch pad positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode. a first set of buttons positioned to be accessible by one or more fingers on a hand of a user while the hand of the user is resting upon the input device, when the user is operating the input device in the 2D input mode; a second set of buttons positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode; and a touch pad positioned to be accessible by a thumb on the hand of the user while the hand of the user is gripping the input device, when the user is operating the input device in the 3D input mode.