I've been to a lot of conferences and so much that is good about getting that many people together are the conversations that happen. I think that applications like the brilliant Intronetworks are great ways to start those conversations beforehand and maintain them afterwards but I've never really seen anything click in that "during" phase.
So we're missing a way to powerfully surface conversations but the good news is that we're not missing a chance for it. Almost every conference with an expo floor also has a reception on that expo floor at some point during the conference. How about this....
First, let's stock that reception with craft beers or craft bourbons (ok, that part isn't critical but I thought I'd include it just in case). Second, we get rid of the drink tickets (don't worry, we'll get to them evetually). Now instead of just getting drink tickets, there is a huge whiteboard or mural-sized slab of paper and baskets and baskets of the finest post-it notes.
The way you 'earn' drink tickets is by writing down and posting ideas from conversations you've had, want to have, people you want to meet, etc. You can also earn tickets by using the yarn that's also available to make connections between the post-it notes.
You're right though - we have to have some QA here so I see people standing off to the side/mingling/browsing, watching what you post and the connections you make and voting somehow (cheers, hisses?) based on the quality of your addition. That's right, your role in the community isn't just to add content but to help the community evaluate that content - think of it as live curation.
The only other piece I'll add is that I'd like this board/process be running from after breakfast on the first day. OK, so we good?