I am using Ubuntu 11.10 with Gnome Shell and unity and I was wondering how to change the desktop wallpaper form terminal or command line .
I found the following but i can't seem to get it to work ,
gconftool-2 --set /apps/compiz/plugins/wallpaper/screen0/options/images --type list --list-type string "[file:/path/to/first.png:100,file:/path/to/second.png:100]"
gconftool-2 --set --type list --list-type string /apps "[file...]"
.