Seth Godin has this interesting post:
If marketing is the art of spreading ideas, then teaching is a kind of marketing. And teaching to groups verbally is broken, perhaps beyond repair. Consumers of information won’t stand for it. We’re learning less every time we are confronted with this technique, because we’ve been spoiled by the remote control and the web.
If you teach--teach anything--I think you need to start by acknowledging that there’s a need to sell your ideas emotionally. So you need to use whatever tools are available to you--an evocative powerpoint image, say, or a truly impassioned speech.