If you found the script which creates an XML automatic changing wallpapers not very user friendly, there is now a GUI for this. It's called XML slideshow creator and you can use it to create an XML background (a wallpaper which consists of multiple images) from all the images in a folder, set the interval between changing the images, the animation time and also directly apply it as your background.

A while ago, we published an article on a script which generates an XML wallpaper set from the National Geographic 2009 wallpaper contest but what if you want to use different wallpapers to generate such an XML file (if you don't know what's this, think of the "Cosmos" automatically changing wallpaper which comes with the Gnome 2.28, like in Ubuntu Karmic)?

ozhoo @ ubuntuforums (thanks!) has created a bash script which generates such an .xml file for Gnome: DOWNLOAD.