I use the CSS3 Animation (some keyframes in it).
Inspired by a sign in on Vimeo. I think it should add some animation from the movement of the sun, clouds, and moon.
This is not to use flash but CSS3 Animation. easy, easy and takes time to add some keyframes in it.
Just easy, cool and spend the time to add some keyframes in it.
work in Mozilla Firefox 5 and Google Chrome.