I have implemented GTD using toodledo with great results & I am loving it.
I work with a team of people and they have all shown an interest. Rather than point them to a book, I would like to get them to get a quick overview of the GTD system through audio/video. I have searched youtube, but cannot really find anything that really covers it off. Have you come across any that you can share?
This isn't a video, but a guy wrote a blog summarizing what GTD is, and David Allen himself commented on how impressed he was with the writeup (The company published this blog on their website too). It may be a bit simple for what you are looking for, but I think it is a great resource.
David Co also made a mindmap of the later book Making it all Work, which visually and concisely condenses the whole GTD system, as well as gives some context and tips on it. I can't find the original source, but you can get a few versions of it attached here-