SyncWall is a basic wallpaper changer with a special feature, the ability to synchronize wallpaper changes between several workstations with a basic (and unsecured) client/server protocol. Each workstation must share the same pool of files, there is no FTP or Internet download. Other interesting features are simple multi-monitor support and the ability to add special effects to wallpaper.
http://sourceforge.net/projects/syncwall/files/1.1.0/
http://sourceforge.net/projects/syncwall/files/1.1.0/