An interesting post. I suppose the main difference is the size of the group you are used to, since larger groups can't hold a single conversation in an interrupt culture. Like Error said, on the internet (assuming threaded posts, that is) interruption is entirely impossible. It occurs to me that among deaf people communicating via sign language, there would be a more interesting phenomenon: everyone can sign simultaneously, and everyone can parse what someone is signing no matter how many other people are signing.