We have a microphone and speaker so it's easy to get everyone quiet. One loud Attention Please works great. The system is cheap, portable, wireless microphone, speaker, and hands free lapel for wearing.
Our biggest problem now is cell phones. We announce that all phone be set to silent but at every meeting someone will forget or not do it, the phone rings a silly ring tone, they search in their purse to find it and then they answer it! Say Hello and continue to talk while walking out the room or worse yet the older ones will stay put and talk. No one wants to seem mean to the old lady so what do you do?