First up read this post ...
Give them the clap they so richly deserve
http://dwighttowers.wordpress.com/2011/11/20/give-them-the-clap-they-so-richly-deserve/

I read it and applied it 2 days ago ... it worked a treat. I came to a point in a workshop where 5 groups had designed prototype models for a project. I always fear the boring-as-batshit, dull and dreary group "report back" ... enter the crowd applause.

I invited the audience to break into spontaneous applause at the 2 minute mark of the group report backs. I provided presenters with a 30 second warning and when 120 seconds appeared on my stopwatch, I held up a yellow card ... to which the audience erupted into applause ... and the speaker was forced to terminally shut-up and sit down. It was beautiful.

My reflections on why this is such a useful strategy ...

1. It adds a participatory element to the presentation

2. The audience takes delight in the power they have over the presenter and over the process itself. Because most of us suffer from the psychological scars of sitting through way too many presentation that go way over time, there is some sort of payback incentive going on here.

3. Presenters suggested that there is no greater incentive to keep to time. I think the thought of their audience applauding them stokes a fear in the heart

4. It's fun and playful. The whole thing is an invitation and an offer that the whole group is part of. 

5. It means that the facilitator or host of the event doesn't have to play 'bad cop'! Often you feel like both the presenter and some of the audience resent your efforts to shut them down. 

I cannot wait to use it again ... next time when the stakes are higher with a paying audience and high-status guest speakers.