SeaDragon is hot. And before the mac fanboy's get all 'leopard already does that,' watch it to the end and see how they've stiched those images together with photosynth. That's pretty frightening, er, amazing.
I think the part that is kind of maddening is that MS acquires these companies and technologies and is really not willing/capable of roling them out to the world, but instead uses them to limit competitors.
If you have the time, you should check out the rest of the TED site. It's really good. Some day I'd like to attend one of their conferences just to get excited about technology again.