Can you hear me now?

My patient's mobile phone rang in the middle of his medical visit yesterday. I was fully expecting him to react as I would in such a situation: apologize and turn his phone off. Instead, he jumped up off the examination table, flipped open his phone and proceeded to talk to his wife for several minutes while I waited to resume the exam. This is a patient I have a good rapport with and have known for a long time. I asked him to please turn his phone off during our appointments from now on. However, I can't help but think: isn't that just common sense? I know patients talk on their cell phones in the waiting room, but am I crazy to think that cell phones have no place during a medical exam? I am tempted to post a sign in my office room saying "All cells phones and guns must be checked in at the door". 

Few days back, I had a family come in all texting on their own phones during the visit. The girl continued texting during the exam, even on her back during the abdominal exam. The mother finally told her this was rude. I really think they were texting each other.
Has anyone had any similar experiences? If so, what has helped you to curb this rude behavior among your patients?