[BlueWing]

For me the worst are the Bluetooth Ear Piece. In public can't tell if they are starting a conversation with me . Have a friend who in the middle of a conversation with me will start talking to his caller it takes a second for me to realize his conversation is somewhere else. So I just keep talking and when he hangs up and asks what did I say I just reply I just lost my train of thought.

Speaker phone - If it is someone with all that background chatter or have the phone too far away I will start using some profanities casually. A round or two of that and whenever they see my caller ID will always keep it off speaker.