Apologies up front for the long off-topic post, perhaps it should be moved to its own thread.
liz: "Did you find anything worthwhile to do with it once jailbroken?"
How about using it as a multi-function accessory module connected over USB to the R-Pi?
"On my kindle I am root"
"Kindle VNC Viewer"
http://www.mobileread.com/forums/showth ... p?t=150434
http://www.amazon.com/gp/help/customer/ ... =200203720
Using a Kindle with R-Pi in this way should be "a thing" with a HOW-TO.
The fact that the Kindle is merely a Linux box makes me wonder about sharing the Kindle's wifi capabilities with the R-Pi. Basically, the aim is to use the Kindle as a server to provide wifi, and as a client to display the R-Pi's screen. While we're at it, it might be a good idea to cluster the two to take advantage of the vacant cycles on the Kindle's CPU...
I'm just throwing all this out there. I haven't done anything more than read the above links and mess around with my Kindle a little, but I'll post somewhere on the forum if/when my R-Pi arrives and I make progress in any of the 3 (screen, wifi, cpu) areas. If anyone else has the time, an R-Pi, and wants to get cracking, this would be a profitable (in the community-utility sense) thing to get going in an organized way. At $80US a Kindle is about the cheapest screen out there, let alone screen+processor+wifi module. An R-Pi + Kindle system might not be any good for watching youtube videos or gaming, but you can certainly browse the web, read, and use emacs on it, and all that outside in the sun!
If all of the above were possible, I'd stick a battery, my Unicomp EnduraPro, a powered usb hub, a few bits of power supply hackery, the Kindle, and the R-Pi in a cheap briefcase and have the best possible laptop for 90% of what I do with a computer.