» #Kindle 4 Custom Screen Savers - Craig Russell Web n That
Early Kindles allowed you to use your own images as screen savers, this feature was removed in later models. Thankfully people much smarter than me had written custom firmware giving you this feature back. Unfortunately this firmware hack doesn’t work with the latest 4th generation non-touch (NT) Kindle.
There is however, still a way of getting this functionality on the Kindle 4 NT, but it is quite fiddly and requires you to have some knowledge of Linux file systems, basic networking and SSH.