Tips on public speaking from Scott Berkun, who presented at work here recently:
1. Don't be afraid of the crowd. If necessary, arrive early, acclimate to the room, exercise beforehand. Amygdala.
2. Don't make it look like it's your first time ("nervous surgeon syndrome"). Practice slides, pitches, video manipulation, etc., beforehand until it feels good.
3. Keep a rhythm. ("Turtle on crack") Let people know how long each segment is supposed to take, be consistent. Attention span: 5-10 minutes. "I've got six pieces, five minutes each." May also be useful to give people an outline to follow in case they drift off for a minute.
4. Keep an interesting angle on things. Make it interesting to yourself at minimum. Also study the audience, talk to the audience beforehand about past experiences.
5. Avoid obfuscation of rhetoric: watch your tendency to use big, obscure words to win arguments (because people won't ask what things mean in an argument). Be clear, bring people along. Don't use language to defend yourself from questions. Do not be afraid of questions! (Side note, trying to make arguments strong: there's a difference between the point you want to make, and the arguments you use to support the points. Points must be clear, arguments can be clarified reactively.)
6. Slides serve what you are saying. Huge bulleted lists are often an indication that you have not practiced this, and are planning to use slides as notes. (Back to the audience, feel obligated to cover every point on the slides, etc.) Makes too many demands on visual bandwidth (information density--speaker doesn't know what the point is). Goal of a slide should be to support your points. If you need density, write a report, make a web site, whatever--but don't do a presentation. The acceptable level of density depends upon the presentation goal and the audience--if you're presenting code programming tips it may be okay to have more density than if you're giving tips on dating. When in doubt, rip it out.
If you're so evil, eat this kitten!
"The presentation or 'gift' of the Holy Ghost simply confers upon a man the right to receive at any time, when he is worthy of it and desires it, the power and light of truth of the Holy Ghost, although he may often be left to his own spirit and judgment." --Joseph F. Smith (manual, p. 69)