I had the pleasure of co-presenting with +Nicole Tomaselli on December 2nd at the "2015 Christa McAuliffe Technology Conference" last week. We created a site and a survey that we tweeted out and posted on FB. We helped teacher connect to the site at the start of the demo and the showed the results to an audience. We had over 50+ teachers attend.
The "Demo Slam" allowed participants to interactively share their best Google Apps for Education (GAFE) tricks/tips. We setup two projectors in the session, so we could rotate quickly between two projection screens to fit in as many 2-3 minute GAFE tips as possible - "Slam."
I showcased, Google Keep, Screencastify, Google Slides (with the chrome extension, Poll Everywhere) and actually polled the audience on their favorite app/extension thanks to +Craig Sheil giving me a heads up and a link to his blog post on this topic!
I used this model in my district last year and loved the collaboration.
I plan to propose a Google Demo Slam and a "Mini Edcamp" model for our PD session next month using the same format from the conference.