Hey you, sitting at that table behind me in this coffee shop! It's a cellphone not a walkie talkie, you nitwit! Take it outside if you want to scream out loud. It's not a conversation unless I hear the other side as well (perhaps you can try the speakerphone on your cellphone and become a certifiable jerk).
Hey you, over there in the neighbouring cubicle arguing furiously on a silly something as if it were the latest problem to befuddle nuclear scientists all over the world! Have you heard of conference rooms? The office surely has one available just to serve your needs. The whiteboards are larger and you can just get on the nerves of a few others like yourself, who presumably understand your babble.
You are all welcome to upload your essence into the Doom continuum as zombiemen. I'd be glad to blow your electronic avatars to pixellated goop.