Just listened to the IT Conversations podcast Great Public Communications Skills which covers Carmine Gallo's new book, The Presentation Secrets of Steve Jobs: How to be Insanely Great in Front of Any Audience.

Two clips Carmine mentions specifically to watch are:

• The return of Steve Jobs at MacWorld Expo 1997.
• iPhone release at MacWorld 2007 (jump to 26min mark)

What I found interesting is that these 2 presentations, approximately 10 years appart, use the same presentation techniques.