Some interesting videos here on running a 3 month old OS on a 16 year old Mac 
I love these pushes of boundaries.
I posted this here once, donkey's years ago, but just in case some of the newer punters haven't seen this, I present full screen, smooth video playback on a TWENTY year old 25 megahertz Quadra 700, with, are you ready for it, 20 MB of RAM and 512K of VRAM. I worked on this very mac back in the day, back when I was involved in desktop publishing. As Dronecatcher said, its all about the codec, in this case, Cinepak.
All of my Macs have Quicktime Pro which includes it - don't know whether it comes with the standard version as that doesn't have any export options.Pardon the n00b question, but how does one get this codec on a PPC mac running tiger or leopard?