A portable device includes a transparent surface; a microlens array having lenslets, each lenslet forming a corresponding image of an object using light received through the transparent surface; a light sensor having pixels, each pixel corresponding uniquely to one of the plurality of lenslets, to detect the formed images of the object; and a controller to use the detected images to determine a motion of the object relative to the transparent surface, and to output the detected motion to a display for use in navigating a cursor and/or a menu on the display according to the determined motion. The portable device can be used in a telephone, personal digital assistant, and/or other handheld devices which control navigation on a display included in the device or external to the device.