I could mod my Kindle so I can now use it as screen for the RaspberryPi. KindleberryPi makes it possible to have a terminal only, but with my guide you can use it as a complete screen!
How-To for Kindle 4 NT:
1) jailbreak your Kindle: http://wiki.mobileread.com/wiki/Kindle4NTHacking#Jailbreak
2) install USBNetwork: http://wiki.mobileread.com/wiki/Kindle4NTHacking#SSH
3) install KindleVNC viewer: http://www.mobileread.com/forums/showthread.php?t=150434
4) now you can connect to your Kindle (the root password doesn't exist, you can type anything) by doing
5) start the vnc viewer with
6) to autostart the Kindle's viewer once the Pi boots up, link to this script (you need to have sshpass and x11vnc installed!):
from ~/.config/autostart/kindlestart.desktop (create the folder if it doesn't exist).
taken from - http://www.raspberrypi.org/phpBB3/viewtopic.php?f=41&t=62139