Yes. I was poking around all the different ways Apple was shaving storage and I found that the Leopard welcome animation (showing the word welcome in different

Yes. I was poking around all the different ways Apple was shaving storage and I found that the Leopard welcome animation (showing the word welcome in different languages in a galaxy) was stored in JPEGs, one for each frame; the Snow Leopard one was finally a video in H.264.