Hi thomass! Thanks so much for your script! Sorry for the late reply!
OK, so, let me see if I got it right:
1) Even if already jailbroken, copy data.tar.gz to the Kindle root folder
2) Also copy runme.sh with your code to the Kindle root
3) Home, Menu, Settings, Menu, Restart my Kindle
4) Copy the images in Kindle/screensaver/
5) The magic is done!
PS: do I need to use the Kindle names for the screensaver files (07N.png, etc...)?
Thanks a lot!