Comment 4 for bug 563269

Just though i'd add what i'm using now. Seeing as xml is eventually going to replace this program anyway I took the script from the comments on the page bellow and updated it a little. Every time I add photos to my dropbox dir I just run the script. Ex. sudo /usr/local/bin/mkwlppr.sh Dropbox.xml 14400 /home/david/Dropbox/Photos/*.jpg

The script now puts the xml files in the right dir so all you have to do is select it in (change background). Of course, could put this in (sudo crontab -e) and have it auto update.

http://pastebin.com/Vs32fMAp
http://www.linuxjournal.com/content/create-custom-transitioning-background-your-gnome-228-desktop