I'm sorry that I didn't see this thread until after the debate.
But if the science folks don't mind hearing out a rhetorician, maybe I can toss in my 2 cents for future reference.
Creationists love these "debates" because, no matter what happens, the simple fact that a "debate" occurred lends credence to their cause. It makes them appear to be a legitimate alternative. This is unfortunate, but the costs of refusing to engage them publicly must be weighed against the costs of accepting invitations to these side-shows.
Probably the best way to prep for one of these is to research the creationist's previous appearances and publications. They count on the fact that their show moves from venue to venue, so they can drag out the same old lies and dodges afresh.
Once you've done that, do 3 things.
1. Study their points, and the refutation of each point, til you have it down cold.
2. Do not use technical terms. Never forget that you're not actually speaking to the creationist -- you're speaking to the audience. Make your argument as simple, clear, and comprehensible as possible. Seek out analogies that others have used which make you think "Aha!" (My favorite example of this tactic comes from Richard Feynman: "In a memorable session of the Rogers Commission (the group that investigated the Challenger disaster) the late Richard Feynman, Nobel Prize-winning physicist, conducted a dramatic experiment. He affixed a C-clamp to a sample of O-ring material, dropped it into his glass of ice water, and then removed the clamp, revealing that the O-ring rubber lacked resiliency when cooled to 32 degrees Fahrenheit." )
3. Bring notecards, whenever possible, with dates, names, and thumbnail comments so you can not simply expose the lie, but expose it as a knowing lie, with lead-ins to questions such as "Dr. X, you made that same argument at a debate in Madison, Wisconsin on August 14, 2005, and you were informed then by Dr. Z that ...." You get my point. It's hard to collect that kind of data, but these guys trot out the same stuff over and over, so if you can pin a few points down, chances are you'll get a chance to use it.
Here's an
excellent site regarding the tactics of Duane Gish.
Here's an
excellent resource for developing counter-arguments.
And here's a
teacher's resource page.
It is often difficult for scientists and science-minded people to keep in mind that debates such as these are not science -- they are theater. If we do not treat them as such, we are going to be outgunned, and left wondering why the public was not impressed with the obvious (to us) truth.
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