Also, I would like to develop my idea. Let's make a K-Meleon Skin format. This format would just be a simple zip file containing a background bmp image and a little avi animation. It will uses the filetype .kms (K-Meleon Skin) and will be directly handled by the K-Meleon client.
So let's say that you click on the link :
http://some_webserver/madonna.kms
And whop, k-meleon will download and switch to this skin.
What do you think ?