So, it happened (without me noticing it until a day later or so): My Kindle 4 Non-Touch now has a broken display, it only works in the upper half.
So, what can I still do with it? It's a 800Mhz ARM Linux appliance with 256MB of memory and 2GB of flash and WLAN, after all. Perhaps it's still good enough to run a Jabber server or a Owncloud installation for 1-3 users... suggestions welcome - perhaps it's even possible to repair it?