There is an interesting post over at Presentation Zen on the "Lessig Method" of presentation. Wow! Take a look and I'm sure you will agree that this is an wonderfully powerful presentation style.
I'm trying to think of ways I can incorporate this into some of the presentations I give. I'm pretty sure it requires a huge amount of rehersal to get right... don't even think about what happens if you lose your place. *gulp*
Anyway take a look, it's worth it!