Anyone who's in charge of motivating employees should check out these hilarious, yet scary podcasts from Despair.com. Then do the exact opposite of what's shown. Even if you're not in the motivational business, check them out for sheer entertainment value.
On a marketing note: After watching these videos, I really wanted to buy the book. How can you use video clips and podcasts to promote your event, your speakers, your message? If you keep it funny, educational, and interesting, I bet it'd help get those fence-sitters to sign up.
Update: Ben at Certified Association Executive points to a promotional video ASAE and The Center are using for the Great Ideas Conference coming up later this month in San Diego. What's weird is that I'm not seeing a link to it on the conference's Web page, or at the Great Ideas Conference Blog, so I'm not sure how it's being disseminated.