AutoWallpaper - Using AutoWallpaper:
AeroWallpaperChanger - AeroWallpaperChanger is another "wallpaper changer" software for Windows 7.
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!!
Pixiv for Muzei 3 - Best Pixiv plugin for Muzei 3
Random BackGround - Random BackGround desktop wallpaper slideshow with advanced features for Windows
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads