Want to see an effective approach to a presentation?  Watch Steve Jobs introducing the IPOD for the first time in 2001. It’s one I share widely with students and clients: 
It’s instructive for its:
- Conversational style, audience-centered language
 - An easy to follow structure
 - Use of rhetorical questions as transition devices (which complement but don’t compete with his spoken words for the audience’s attention)
 - Simple graphics and visual aids
 - Judicious repetition of key points
 - Energetic vocal variety (particularly his varied pace)