If you are one of those who always gets bored of seeing the same wallpaper on your screen, and need to always change the image, then you will like programs like Caledos.
With Caledos you can change your wallpaper periodically and automatically, with the frequency you decide beforehand. The minimum period is once a minute, the maximum, once a day.
Caledos lets you create image lists (similar to playlists), it accepts wallpapers in diverse graphic formats (BMP, JPG, GIF), and lets the user arrange the wallpaper how they like. Central images, mosaics, expanded, with or without borders, etc. On top of all these options and configurations, you can store each image separately, so that if you wish to use an older design, you don`t have to repeat all the adjustments.
NOTE: for it to work correctly, Caledos needs
Microsoft .NET Framework installed on your PC.