The Kindle comes with some stock screensavers, but you soon get tired of them. You can’t change them as easily as you change the wallpapers in your PC. The process involves getting into the diagnostics mode, enabling USBnet, SSHing to a server and moving some files. It’s not as scary as it sounds though.
If you use Linux, the process is less messy. I followed this guide and everything worked fine, except the password mario didn’t work. However, I could generate a password by entering the serial number in Amazon Kindle root password tool. A directory called ‘screensaver’ gets created in the Kindle, to where you can copy any jpg or png files, preferably 600×800 grayscale images.
If you use Windows, the following two videos will guide you through the process:
Getting into diagnostics mode: http://www.youtube.com/watch?v=XZEhsCKgMHw
Changing the screensavers: http://www.youtube.com/watch?v=fG_pGDMsAYo
I also created an album of Paulo Coelho Kindle Screensavers. You can view and download them from here: http://imgur.com/a/QRDq6
Or download them as a zip file from here: Dropbox link