Many eons ago when I took a class in public speaking, I learned the fundamental rule of public speaking, including for presentations: It goes like this - say what you are going to talk about, say the full thing, say again what you just said in recap mode. (intro body conclusion).

Also, speak with some authority in voice which will only come from a lot of practice and full knowledge of your presentation material. Practice it in your room with live PPT, identify spots where you tend to stop or tone down, refine the material for that spot.. and again and again.. If you are not convinced of your own presentation, your audience won't be either.

If you are using PPT (or any projection method), do not come in the way of projector and screen. And do not stand in front of the screen.

Opening: with your title slide, do your introduction (the 'say what you are going to talk about bit') so that the audience will pay attention to you and not to the slide, which, at this point, should have your presentation title, your name, etc.

Closing: Don't have the 'THE END' slide. Instead, use some relevant and catchy quote, and a small Thank You note on the same slide.

BTW just read this opener at fastcompany.com "Please say who you are, what you do, and how the Web is screwed up." How's that for an icebreaker? That was the way Kevin Lynch, Adobe's CTO, grabbed his audience at the company's annual developers event this year, throwing open a discussion about what we don't like about the Web and what we'd like to see fixed. ..." (http://www.fastcompany.com/magazine/125/how-to-fix-the-web.html).

_x