How to run a great unconference session

For those of you don't know what an UnConference is, here's a wiki explanation:

"An unconference is a facilitated, participant-driven conference centered on a theme or purpose. The term "unconference" has been applied, or self-applied, to a wide range of gatherings that try to avoid one or more aspects of a conventional conference, such as high fees and sponsored presentations. For example, in 2006, CNNMoney applied the term to diverse events including BarCamp, Bloggercon, and Mashup Camp."

It's a great event to discover ideas outside of your usual social life. For example, At one UnConference a girl shared about her experience swimming across the English Channel, a guy brought in a 3D printer and showed how to print 3D objects, and I even learned how to juggle in one of the sessions!

One for my growing "Great Artices" collection.