Most of us have been annoyed in a restaurant or on the road by a loud or distracted cellular phone user. A cellular etiquette campaign is now being launched in Iowa.U-S Cellular lays out rules in its public service campaign, advising cell users to respect quite zones, like churches, theatres, courtrooms, classrooms and meetings. It says cell phone users should not talk while on the road if it impedes the ability to drive.Todd Walker, U-S Cellular’s general manager for western Iowa, says cell phone users must always think of the people around them, not the caller. He says the company now has more than 400-thousand customers in Iowa.Walker suggests people use the vibrator function or voicemail instead of letting the phone’s ring disturb others. Despite smaller handsets, he says callers can hear you just fine on a cell phone — there’s no need to shout.