How to Finish a Talk
Every year at MIT, Professor Patrick Winston gives a talk to his students about how to give an engaging lecture. While his entire hour-long lecture contains several nuggets of useful information on presentations, I was particularly interested in the few minutes he devotes to ending a talk before taking questions. (Just click on the section, "How To Stop")
First, he says you should give a quick summary of what you've promised to tell the audience and a few lines about how you've accomplished that. Then, perhaps counter-intuitively, he states that you shouldn't thank your audience for their time. That leaves them with the subconscious sense that they've done you a favor. Instead, he says you should say something along the lines of, "This has been a wonderfully stimulating experience for me, and I look for forward to talking to you more about this in the future."
(Via BoingBoing)