Oh, we did, believe me we did. We endlessly tried to remind speakers and audience people to use them.
In fact, in many of the sessions, we did our best to run around and try and pass the mike around, or get the audience members commenting to come up to the standing audience mic, or have the speaker repeat the questions.
Surprisingly, we found it really hard to achieve any of those solutions.
There's no question, getting up or waiting for a mic to be passed around inhibits the conversation flow significantly. For most of the other rooms, this wasn't a problem as they were smaller, everybody could hear, and we weren't taping. The discussions in those rooms, I unscientifically and possibly inaccurately contend only to make a point, were much stronger and free-flowing than the whole "wait for a mic or get up to talk" kind of environment.
I haven't seen all of the videos yet, but if the end of the Rostedt talk got recorded, you'll see how we tried.
And for Linus's talk - it was too packed a house for anyone to get up. They had some mics in the back and the sides but they seem to have caught almost none of the audience questions. It was valuable to have people speak up freely and have Linus pick on the questions, and I just had to hope that from the answers most of the questions were probably self-evident or derivable from context.