Richard, Dien & Dan,
... and I admit I'm VERY biased, but in my opinion, the best in the business at this stuff is Kenrick Cleveland.
I met Kenrick in 1989. He was Jay Abraham's sales trainer at Jay's Protege seminars. I've never seen anyone capture an audience the way Kenrick does. He was far & away the most popular speaker at Jay's seminars.
We've since worked together on several projects, and I learn everytime I talk with him.
He has tape courses & an ezine available at the link below.
Richard Dennis
http://maxpersuasion.com/