[img]http://newstop.googlepages.com/MoonTransit.png[img]
The lunar transition in 2007 from the STEREO-B Observatory.... in Animated PNG (hushed awe). You'll need Firefox 3 or Opera 9.5 to animate it (so its a good time to upgrade), but everyone should be able to see the first frame.
If you want to make your own Animated PNGs you can use the program below which unlike most APNG makers so far 'will' produce an optimised file.
http://newstop.googlepages.com/tga2apng