ThetaWall is a highly customizable wallpaper changer

Windows 7 testers already have wallpaper slideshows at their disposal. Users of previous versions have plenty of freeware options to add automatic wallpaper changing to their desktops - like extremely flexible ThetaWall.

Apart from changing the all-important basics like the interval between changes and auto-scaling, Thetawall can also generate collages from your images. It also plays well with dual monitor setups, automatically detecting wallpapers designed for display across two monitors. For an inbotrusive heads-up date display, you can check off the "add calendar to primary screen" option.

The download also includes a screensaver, allowing you to view your images and collages when your system is idling. One downside: ThetaWall only looks for images in the folder you launch it from and its subfolders. You can, of course, set up a hard link to point at your existing image folders instead of copying them with a utility like Link Shell Extension.

ThetaWall is a free download for Windows and requires the .NET framework.