Who here has successfully used teleseminars?

I am looking at using teleseminars to connect further with my clients on my next information product. My questions for those here are:

What formats have you used to make the successful? (Guest Speakers, Reading your books, Yoddeling)
How have you used them to build lists?
How have you used them to earn revenue?
What resources / teachers have you learned from on the internet about doing them successfully?

Let me know.