PowerPoint karaoke--where people pick up random presentations from the Web and wing 'em in front of an audience--is no longer just for geeks, according to this article in the Boston Globe. Here's how it works, from the article:
In a typical event, a few brave people volunteer to "present" a random deck of slides pulled off the Web, or borrowed from friends or employers. (I first heard about PowerPoint Karaoke when an organizer asked if she could use a deck I had presented on word meanings.) The audience laughs, cheers, and yells out suggestions as the presenters gamely struggle to link one slide to the next, transforming something that probably started life as a tedious corporate monologue into a five-minute flight of creative irony.
I can't imagine you could use it in any formal way for a conference, but how much fun would it be to incorporate it into a social event? The article does say people have been using this at meetings, but doesn't explain how. But you all are creative, so I'm sure you can come up with something.