Scott Kirsner wrote a great article called “12 Guidelines for Great Panels.” Check it out here. If you read “How to Be a Great Moderator” and “How to Kick Butt on a Panel,” you’d have panels down to a science.
I have an additional insight regarding panels. Most panels have audiences of 100 to 250 people; however, approximately 20,000 people watched Churchill Club’s “Startup 2006” panel (Veotag version, Google Video version). You could have knocked me over with a feather when I learned of this number. More people probably watched this panel than any other panel in the world in 2006. :-)
Online audiences of this magnitude impacts every panel in several ways:
The size of the audience at the event is not nearly as important as whether it will be recorded and publicized. With the online video, there’s no such thing as a small audience anymore.
No matter how small the physical audience and obscure the event, you’d better be on your toes and give a great performance because tens of thousands of people might see it. With online video, there’s no such thing as a “small slip up.”
Best case: look at both the audience and the camera. Whatever you do, don’t look at only the moderator unless you want 20,000 people to only see the side of your face.