A little while back, I was working for a very cool company called Bitscribe which does weekly conference room users' group sessions. I did two sessions there, and there was a very interesting contrast. The first session, I forgot to bring the video adapter I needed. So I basically just did a session on the whiteboard. The second time, I had the video hooked up properly, and not only that, I had video clips and audio as well.
The first presentation was awesome, and the second presentation stank. Nobody really cared during the second one. People responded sluggishly, if at all. The first presentation had more questions, more ideas; there was tons of actual code on the whiteboard, and a lot of it came from the other people in the room. I think everybody in the room spoke more than once. In fact, by the end of it, I wasn't even the only person at the whiteboard.
More recently I gave presentations at OSCON and Ruby East. Exactly the same thing happened. My OSCON presentation was full of funny pictures that nobody laughed at and clever comparisons that nobody was interested in. At Ruby East, I didn't even bring any presentation materials at all. No slides, no transitions, nothing. Just code. People loved the presentation; a couple guys who were saying afterwards that conference presentations needed to raise the bar in general actually went on to say "like your presentation," which was a huge compliment.
At OSCON, although people were into what I was talking about, I felt nervous the whole time, and I still feel I could have done a much better job. At Ruby East, I was calm, confident, and having fun.
The Keynote-less presentation at Bitscribe, we came up with an idea for a new twist on Rails, discarding its templating system in favor of a Seaside-like components system. We fleshed out actual code in the process, although we didn't go so far as to actually make it work. At Ruby East, we did go that far. An audience question which was basically a feature request led to a gigantic but very quick group hacking session, which resulted in new, useful code.
The secret sauce: before Ruby East, I read some blog posts by Kathy Sierra, which reminded me of the two presentations at Bitscribe. The posts were all about how to get people interested in your presentation. One tip: don't introduce yourself. Don't even bother. She said that presenters who start out giving you their credentials are way off base, because people don't need to know you're qualified. They assume you're qualified, or they wouldn't be at your talk. To quote:
Trying to establish credibility is backwards. Don't try to get the reader to respect YOU... the reader wants to know that you respect HIM!
You can take that one step further. Don't try to get the people in your presentation to imagine that what you're talking about probably works. Just show them it working. It was good enough for DHH when he first demoed Rails at RubyConf, and it's good enough for you too.
I still dig Keynote for screencasts, but I think I'll probably never use it at a conference ever again.