Just came across the very cool Webilder program for gnome (and kde) which runs as an applet - automatically downloading flickr and webshots images and setting a new one as your background at a specified interval!
Get it at Webilder.org
For fedora users I built some fedora core 6 packages located here
python-webilder-0.6.2-1.noarch.rpm
python-webilder-gnome-0.6.2-1.noarch.rpm
python-webilder-kde-0.6.2-1.noarch.rpm
Installation
For gnome
sudo yum install gnome-python2 gnome-python2-extras \
gnome-python2-applet python python-imaging pygtk2
then install the rpms with
sudo rpm -U python-webilder-0.6.2-1.noarch.rpm python-webilder-gnome-0.6.2-1.noarch.rpm
For KDE
sudo yum install PyQt-devel PyKDE python python-imaging pygtk2
sudo rpm -U python-webilder-0.6.2-1.noarch.rpm python-webilder-kde-0.6.2-1.noarch.rpm