Marco already posted on this, but I thought I'd pitch in our side of the story.
At php|works, this year (a couple weeks ago), our /fear(some|ful)/ leader was absent. He had some personal stuff that conflicted with the conference's schedule, so he left it in our (Paul, Arbi and myself) mostly-capable hands.
I think we did a good job, even without him, but to deter him for deserting us at our [bigger!] spring conference, we came up with an idea... a good idea (-:
Tradition states that Marco should give the closing keynote at our conferences. This time around, we had excellent internet connectivity–thanks to the nice folks at OneRing Networks and a little experience (read "don't trust the hotel's AV company for networking needs) on our part–we (Marco and I) decided that he could reliably give his keynote via iChat. The idea had not yet been conceived...
We try very hard to make our conferences professional but not uptight. Some ideas works, some don't. This one did (-:
We devised a way that we could harness the audience to "caption" Marco's closing keynote. It involved 15 minutes of coding, 2 laptops, 2 projectors and an unsuspecting boss.
Here, this probably helps:
The first projector displayed the output from my laptop's iChat window, so everyone could see Marco's lovely mug. The 2nd projector ran a web browser that displayed the audience-sourced caption (updated every 5 seconds).
Oh, and as I alluded, he had absolutely no idea we'd done it until a few days later when I let the cat out of the bag–I figured it best that he hear it from one of us than read about it on someone else's blog.
We had fun, and I distinctly remember hearing "Best Closing Keynote EVER" after we logged off. Hope you had fun, too (-:
UPDATE: Oops. Almost forgot to link the video.