SpaceSuit

Customize Spaces with a different desktop picture for each Space.
With SpaceSuit, you can set your background images via a simple drag-and-drop.

And changing the display settings is as easy. SpaceSuit's minimalist interface is contained in its dock icon: all its options can be accessed from the icon menu.
SpaceSuit also uses Leopard's Core Animation. Everytime you change an image, resize it or modify your display settings, SpaceSuit adjusts your desktop with a smooth animation.