miniature TED conference. 6-10 people.
Format: either copy TED and have subsequent discussions, ie, someone speaks and is uninterruptible for a while, then joins the group and discussion under some moderation, or
guided discussion of topics by moderator, or
someone speaks and is interruptible as they go, with/without moderation, discussion either being good to go in the middle, or not.
Initial group of people would have a technological bent - is this unfortunate? Perhaps. Definitely not limiting it to tech.
possibility of a rule similar to ko: if an argument breaks out, it can not continue more than two or three 'plays' - person A says "True", person B says "False!", person A may then say "True, because (argument)!", and person B may then say "False, because (argument)!" - but at this point, Person A may not respond again to defend True. Both sides have spoken twice, and the conversation must move on.
Or something like that. Anyway, going to keep developing this.