Lot's of good advice above.

I too am a big fan of Jeff Veen's speaking style. You know why? Because it doesn't feel like a presentation. It feels like a conversation or a narrative. I think an interesting variation of asking the question that you asked is this. Tell me what you as an audience member appreciate in a presentation (as opposed to asking presenters for presenting tips).

1- Think of it as a story, not a presentation. 2- Instead of bulleted Powerpoint or Keynote slides, consider diagrams, interactive demos or photos. 3- Consider not using slides at all. One of the best presentations I recently watched at DUX 2005 involved no slides, but tools and utensils to demonstrate how Indians made coffee. She then continued to draw analogies of the cultural significance of Coffee to other person to person and computer to person relationships. It made me want to read her paper. 4- Know who you're talking to and their level of expertise. 5- Don't wait till the end to answer questions. It kind of makes it feel like you're just powering through to get to the end. Also, this makes it feel more like a dialog than a monolog. 6- I reiterate what others have said. Know your shit. Backward and forward/ up and down. 7- Relax. Well, at least try. A shot of scotch ten minutes before might help. Unless, of course, you're an alcoholic. Don't take it so seriously. Audiences can sense stress. 8- Always give them something to walk away with (Tufte) 9- Arrive 15 minutes before (Tufte) 10-Finish before you're supposed to (Tufte) 11- Others here have said practice, practice practice. I think that that's a little less important than just knowing your shit. Truly knowing your shit will prevent others from thinking you're full of it. In lieu of practicing in an empty room, I usually stare at each slide, and go through my notecards to cement it in my head. If I need help with the actually delivery, I usually just talk to myself in the car and record it in my voice recorder. I then listen to that over and over.

The key thing is that everyone is different. Different things work for different people. In fact, I'd be interested in how much prepartion Jeff goes though because it always looks like it's flying out of his head. Like butter.