For those of you who didn't already knew this :
it is possible to run some (most?) X applications in the root window (the window which KDE uses to paint your desktop on) which makes for some pretty cool desktops.
I've found the best way to do this is the following:
remove all icons from your desktop (for best effect,else it's a bit ugly) and setup a black background picture (just make a png with the gimp of the size of your desktop and fill it with a black colour)
go to desktop options under KControl and check the "enable desktop applications" checkbox
goto the dir which holds your X screensavers (usually something like /usr/X11R6/lib/xscreensaver) and run one of the screensavers like this :
./xflame -root &
(or alternatively put the command in some startupscript so it gets executed everytime KDE loads)
have fun
