A portable handheld electronic device contains a camera lens and accelerometer to allow a user to control voicemail and call features by swiping his finger across the camera lens and/or tapping the device. Therefore, the user can comfortably input commands into the device with a single hand and without needing to move the phone away from his ear to apply these inputs. In another embodiment, the camera lens can also be used to control navigation of the display screen or a displayed document of the device. For example, if a user wishes to shift a scrollbar for a page displayed on the screen downwards to view the bottom of the page, the user should move his finger over the camera lens in an analogous downward direction.