An improved handheld electronic device and an associated method provide added convenience for the user by enabling the user to quickly and easily initiate telephone related functions from applications other than the device’s phone and address book applications using a dedicated phone related key. One or more attributes are displayed to the user in a graphical format. The air pollution sensor system comprises at least one soot particle sensor capable of sensing soot particles with a diameter in a range of approximately 5-500 nm inside said enclosure and providing a pollution information signal in response to the sensing of said soot particles. The second graduations have a second magnetization direction different from the first magnetization direction.