GTAC 2013: Drinking the Ocean - Finding XSS at Google Scale: https://www.youtube.com/watch?v=rd5TZKRg-lc (from Google Test Automation conference).
Google I/O 2012 - Security and Privacy in Android Apps : https://www.youtube.com/watch?v=RPJENzweI-A
This one is fun to watch. (GTAC 2011: Keynote - How Hackers See Bugs https://www.youtube.com/watch?v=onpxOG3TrWg) Not technical, but good for a bus ride.