Mitch Joel, President of Twist Image is by far one of the best keynote speakers around. Period. Every single word that comes out of his mouth is extremely insightful and thought-provoking and if you are interested on marketing, social media and/or digital communications you simply must watch him in action.
The presentation is broken-down into four parts and its duration is around 50 minutes. Trust me, I know how valuable your time is, and I can tell you that watching these 50 minutes is most definitely worth it.
By the way, if you have not done it yet, please do yourself a favor and subscribe to his remarkable podcast Six Pixels of Separation. I can guarantee you that you will get huge value from it.