Vintage floral graphics supplied by the Graphics Fairy Blogspot [link]
Text of course, comes from the wonderful "Captain Blood" by Rafael Sabatini, which is in the Public Domain.
Resolution: 600 x 800 pixels. The colour palette has been configured to suit the Kindle, so it displays nicely. I use the Kindle Keyboard, but it should display fine on any Kindle with the same screen size.
To replace stock screensavers with custom ones, you will need to jailbreak your Kindle. Excellent tutorials can be found online, just make sure that you find one appropriate to your specific model and serial number.