When John Gruber did his "zoom" video edition of his podcast the Talk Show (back around WWDC), the video wasn't actually zoom. They used zoom for live interaction, but everybody had an iPhone mounted above their laptop screens for the actual recorded video and audio which was composited in post-production.
It's funny that Zoom disappears in the final product. The audio feed is recorded and re-synced on each source machine with a different software and sounds like the same with the video feed.
