I was just on a webinar that included 110 people. When questions were opened to the attendees there was a choice of either asking a question via chat, or saying it into the phone. Leaving phone lines open for 110 people meant we also heard dogs barking, phones ringing, people being greeted, and lots of coughing.
When taking questions from the crowd on a webinar, I believe all should have to submit questions via chat, submit questions in advance, or some method where a question can be asked without 110 phone lines open "for sound". It was remarkably difficult to hear until they muted all the lines to hear the answer.
The same is true with live forums involving larger groups. When the floor is open for anyone to ask anything 3 things are nearly always guaranteed to happen: a) a huge amount of time spent with people giving random thoughts on any topic whatsoever (may not even involve a question)- which frankly can waste everyone's time; b) an emcee might be running around the room with a microphone which also takes a huge amount of time with everyone watching the person run around; c) those in the audience start yelling out questions thinking they are "loud enough" (when they aren't) and everyone sits staring and not hearing the question, which then has to be repeated. Or not repeated, then attendees in the back start openly yelling "use the mike, use the mike, repeat the question, repeat the question."
The better way to handle crowd questions, in my opinion:
1. Distribute index cards and have someone other than the main emcee collect them during the presentation and during question/answer period;
2. Set up microphones and require all to go to them. Instruct at the start of the Q&A that time is for questions, and to please refrain from additional comments not directly related to the topic;
3. If webinar, as mentioned above, require use of submitted questions, chat, or a service feature that blocks out any sounds other than the phone line of the person notifying that he/she wants to ask a voice question on an individual line.
And I've already blogged about my personal pet peeve on any conference call: no talking about the weather when you're using other people's business time. Start the call, conference or webinar on time without extraneous openings or time-wasters.