ubuntu multiple wallpaper 4r ur workspace

Disable the "show desktop" feature in Nautilus. The process to do that is
1. Press ALT+F2
2. type gconf-editor press enter
3. navigate to Apps --> Nautilus --> Preferences
4. Uncheck "show desktop".

Part 2
1. Press ALT + F2
2. type CCSM
3. on the left click on Utility and then on wallpaper
4. select the same number of wallpapers as the number of workspaces.
UR DONE :)