I own a cellphone although I didn't buy the #@%$# thing. It lives in my car and is only used to make outgoing emergency calls.
I am saved from student cell phone usage in my classes by the wondrous fact that our classrooms are about 20 feet underground. No one gets cell phone reception, hurrah. Get to watch lots of people running out the back doors (which are at ground level). Unfortunately outside my office door is close enough to outside so that I often get to listen to idiots.