"The most awesome 450-page presentation ever." That's how the authors call this slideshow - and I agree. It is awesome. But knowing that it was made using only Google Docs and no extra software whatsoever, makes it truly unbelievable.
You can see part of the creation process - which took three days by three animators - in the complete YouTube Video. If you are really curious, you can access - and playback - the gigantic Google Doc that was submitted to Google's Demo Slam.