Looking at this presentation (which blows you away):
OSCON 2005 Keynote - Identity 2.0 makes me wonder (again): how does one achieve an optimal viewer experience? Making your audience feel that the speaker is cool and knows it all could be a goal but it's not mine. I want people to learn to think for themselves based upon (objective) information, thinking capabilities and an inquisitive mind.
They don't have to think I'm cool; I want them to share my passion for the subject.