There is a guy on YT who does these mini-anime (multi episode) of stick figures fighting each other. The opening sequence happens on a PC desktop against a virus. It is just amazing and that whole sequence as an animated gif would make a great screen saver. Now if it could be made dynamic so it works on the existing screen (like xmelt) it would be great.

I would actually settle for the original (non dynamic) one. The one thing you would miss is the sound effects which are also great.