My colleague (Mr. barbd) has bought this interesting concept to my attention - the "Unconference". It's actually pretty well established, but new to me - and so I thought I'd mention it here.
The general idea is that the structure of the average conference allows people to learn from leaders in their field, but an opportunity to learn from your peers falls by the wayside. Some of this happens in a social context around a conference, but its too random and therefore theres a good opportunity there to be taken.
As I've mentioned here, I love the idea of the quieter members of the group being encouraged to speak up. They wouldn't be too timid, otherwise they wouldn't be there (knowing the rules about participation), and it would be have a small-but-open forum in which to challenge pre-conceptions and share experiences on a topic that everyone involved is passionate about.
Strong mediation would be essential though. The worst thing that could happen in this situation is where someone takes it upon themselves to educate the group. The shared knowledge of our peers is surely far more useful than that!