Those of you using Windows Vista Ultimate might have installed Windows DreamScene™ as an Ultimate extra. But not much of choices were there for these high-definition video backgrounds.
Though Windows DreamScene supports .mpeg and .wmv video file formats, but .Dream files were limited.
So here's a tool from Stardock called DeskScapes, which will allow any video or 3D animation to be converted into a .DREAM file, which can be set as background in Vista Ultimate. And its free to download. So start making your own .dream s.