While the presentation is short, there are several golden chunks of information here:
Google Chrome and Mozilla Firefox recently held a video call using nothing but two web browsers and WebRTC (Real-Time Communications):
Does this replace the need for Skype??
Here are a few other resources on the subject:
A real-life case-study of CSS performance issues, and how GitHub solved the problems.
The video is here:
And the slides are here:
This might seem a little intrusive, but I think only because they use so many steps in their example, but I also think it could be a cool tool for us to use for introducing/explaining new sites/products: