Windows 7: Screen Orientation and Wallpaper Rotation (on Tablet PCs)

On Tablet PCs, screen orientation can be changed so that any side of the screen can become "the bottom" of the desktop.
Unfortunately, the result is that a wallpaper intended for a 1200 x 800 desktop, is stretched to fill a 800 x 1200 desktop. See the effect in the attached images.
Is there any way to lock wallpapers to a physical side of a screen?

The easiest solution may be a tiled wallpaper. Something that's just a pattern.

edit: I found this page. I have no idea if it works. I only have desktop machines:

http://www.tabletpcpost.com/modules....Wallpaper_Gyro

The software you linked to is very close to what I'm looking for. It makes it possible to define a separate wallpaper for landscape and portrait orientation.

It'll do very well until I find a utility or method to lock (or auto-rotate) a wallpaper to keep it aligned to one side of the physical screen, which is a matter of esthetics.

I appreciate you taking the time to look for a solution.