Ron down at the computer repair shop showed me this trick on his Red Hat system to run screensavers as a desktop background. Works on Ubuntu also.
dirand select a filename.
./filename -root &
kill replacewithpid#to stop the process.
./filename --helpwill give you more options for individual screensavers.
Webcollage is an xscreensaver that grabs images from the web and uses them to form a collage in the root window.
./webcollage -root -dictionary /usr/share/dict/american-englishto run. Note that you can use your preferred dictionary by specifying the path.
sudo apt-get install netpbm libjpeg-progs