I haven't found the modified sample, but you can download the original code (linked in the WWDC video description) and modify it by following the instructions in the video. At least the slide showing how to preferentially detect and use an external camera is visible for a few seconds, I haven't bothered with the rest yet (which deal with hot plugging etc). It is a couple of lines of code to changes to get a picture from your external camera.
Topic:
App & System Services
SubTopic:
Core OS
Tags: