<BODY>
tag's BACKGROUND=
attribute, produces a seamless screen-filling animation.
If you get jerky or jumbled animation, try reducing the size of your window -- I've noticed that my home machine just isn't powerful enough to render all the frames simultaneously.
Here, with apologies to Rene Magritte and professional animators everywhere, is my first effort.
And here's my second. This is my AIM buddy icon (I'm "FunnyPolynomial").