The Semantic Web Landscape: A Practical Introduction
This video lecture provides a current overview of the Semantic Web landscape, and is suitable for those new to the space. It was originally designed for MBA students at MIT's Sloan business school and has been given many times to different audiences.
This recording was made at the Cambridge Semantic Web Meetup which meets regularly in Cambridge, MA USA. Note that the "Cambridge Semantic" in the name is merely coincidental with the company Cambridge Semantics.
This lesson is relatively long, so you might want to bookmark and come back later if you don't finish in one sitting.