"Continuing in this series of slide show backgrounds, in this
article I will explain the process of creating a set of desktop
backgrounds that will transition like a slide-show in XFCE. Note
that I am using XFCE version 4.6.0 in this tutorial. Other versions
may be able to use this tip, but the screen shots may look
different. See corresponding howtos for GNOME, and KDE3 also.
"Start by right clicking on the desktop and choosing "Desktop
"Under the "Background" tab, choose "Image List". Click on the
green plus sign near the left side of the center of the window to
add backgrounds to this list."