"Inseperable from Magic: The Manufacture of Modern Semiconductors" — an overview of semiconductor fabrication (and its current challenges) by a former Intel engineer. http://www.youtube.com/watch?v=NGFhc8R_uO4

"The Atomic Level of Porn", by Jason Scott — a history of low-bandwidth pornography, from ham radio to telegraphs to BBSes. http://vimeo.com/7088524

How to build your own X-ray backscatter imager (aka "airport body scanner") by Ben Krasnow http://www.youtube.com/watch?v=vUf75_MlOnw

"The Secret History of Silicon Valley" by Steve Blank. Other, more recent versions of this talk exist, but the audio quality is poor in them. https://www.youtube.com/watch?v=ZTC_RxWN_xo#t=1m42s