Great post. I have some tips on my own site (which I won't link to directly, as that's a little shameless, even for me). There's one trick that I learned from a psychological counseling class that has come in handy a few times. If you're having difficulty with something (be it a patient's problem or a presentation), be honest and share the problem with the audience. It's your first presentation since middle school and you're a little nervous? Feel free to mention it before you get going. No one's going to fault you for it.

My last presentation was nearly killed by a laptop disaster. The host thought I was going to bring my own laptop, I thought the host was going to be providing one. All I had on me was a CD of my slides. My slides for a presentation on visual perception. Luckily we realized our mistake about fifteen minutes before the presentation. After calling everyone we knew, I was able to call in a favor from my former employer at the university. It did require, however, that I run across campus, make sure the laptop had everything I needed, and then run back to the classroom. I arrived just in time, out of breath, sweating, and a little disheveled. Then it was time to present.

"Before I get started, let me just take a moment to explain why I look like this. We discovered, just moments ago, that we had no laptop for this presentation. So we called, um," I looked at the host, "Everyone?" I looked back at the audience, "Everyone. And luckily we were able to get a laptop in the nick of time. It involved a lot of running. So again, sorry if I'm out of breath for the first bit of this talk."

It went over really well, and the presentation was very well received. :-)