On September 2012, Jack Dorsey delivered a great keynote at Disrupt SF.
The Co-Founder of Twitter and Square is a great speaker and we can take pointers from his delivery style.
Here is another great presentation from Jack.
Back in May 2008, the then Twitter CEO Jack Dorsey provided a compelling overview of the service and his own inspiration.
[Video length: 14 minutes]
Jack Dorsey Presents Twitter from biz stone on Vimeo.