I came across this by accident and switched back to a normal desktop background quick smart. We used to be concerned about too many icons on the desktop taking up valuable system resources. Vista however lets us take this one step further with a useless but crafty feature.
We are now able to play Windows Media videos as the background of our desktop as well as Windows Dreamscene content. This is a Windows Vista Ultimate Extra.
Windows Dreamscene content is things like waterfalls and other nice things which I don’t really have an interest in. There may be a few more interesting looped movies in the future. Developers could do some great stuff with this.
I can’t see much use for setting this up as you would generally have programs open over the top of it. You can’t play DivX films or the like under it. Saying that, I like to use a proper media player to do this.
It’s fun to have a play with but for me, this will be forgotten about quickly.