Becrux Wally - Wally is a Qt4 wallpaper changer, using multiple sources like files, folders, FTP remote folders, Flickr, Panoramio, Ipernity, Photobucket, Buzznet, Picasa, Smugmug, Google, Vladstudio and deviantART images. Now it's available in many languages!!
AeroWallpaperChanger - AeroWallpaperChanger is another "wallpaper changer" software for Windows 7.
DesktopSlides - DesktopSlides is a light and user friendly desktop wallpaper changer for windows.
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Artpip - Artistic wallpaper for your desktop, refreshed daily.
Wallpaper Cycler - NuonSoft WallpaperCycler is a powerfull utility to manage all your wallpapers and to automatically cycle between your wallpapers.