Desktop Drapes

• Homepage: http://drapes.mindtouchsoftware.com/
• Launchpad-Site: drapes
• Package: drapes

Has some problems under Karmic Koala (e.g. the thumbnails are not shown, crashes if you delete a selected image). The list of enabled images is kept in ~/.gnome2/drapes.xml.

Wally

• Homepage: http://www.becrux.com/index.php?page=projects&name=wally

Seems to not work in Karmic.

Wallpaper Tray

• Homepage: http://freshmeat.net/projects/wp_tray/
• Package: wallpaper-tray

It is a panel applet which shows a small thumbnail of the current active image. It will show images from your selected directories (in the preferences) plus all images in ~/.gnome2/backgrounds.xml (see #355081). Seems relatively stable and is my preferred choice among these 3.