Here is a little app I put together to manage my desktop wallpaper. It is free to use and I take no responsibility for it either working or not working. If it works, have fun!
Download Installer (501k) – Version 1
What does it do?
This app figures out how many desktop screens you have. In theory, if you have one screen or multiple screens, it will create a tab for each screen. From the tab, you can select files, or a directory and all the files in it, as well as any files in any sub-directories.
Once you have added files, you can click on a file name to view the image. Click File->Set Wallpaper to change your desktop immediately using the images you selected (note, you have to select an image from each tab, otherwise the screen will be black).
The app also has a slideshow mode. Click Slideshow->Slideshow Mode to start. Select Random to mix it up. The interval can also be changed.
This is a version 1 release. It is a bit rough around the edges. It is open source. The source code can be found here: http://pathfinder.rsbauer.com/svn/repos/wallpaperchanger/ (user name: viewer, password: viewer). This is a subversion repository. If you wish to contribute, let me know.