Barnes and Noble has a free set of Alice in Wonderland "Screensavers" for the nook that anyone can download. If you have a Kindle, these fit fairly well as is or can be resized easily if a bit of the lower part of the image gets cut off.The procedures for installing a custom screensaver differ for the various models, with the latest ones requiring various hacks to be installed, but I've already put the evil Cheshire Cat on my original Kindle (after adding my name and phone number, in case the Kindle gets lost - it's easy for anyone to find my contact info to call me and more difficult for a thief to claim ownership).
