My experiments with downloading kindle files from the Internet Archive have not been an unalloyed success. Some of them are too garbled to be easily read. Two of them were completely different books to the book described. One of them crashed my Kindle and I needed Amazon's technical help to get it up and running again. On the other hand, I've managed to get a complete collection of Peninsular War memoirs from members of the 95th Rifles and the regimental history by Sir William Cope, and it is a lot easier reading them on the Kindle than in PDF form on my computer screen.
On the plus side, I've discovered the cheap classics sold by Amazon and am building up a huge library just because I can. So far I have the complete works of Thomas Hardy, George Eliot, Charles Dickens, Leo Tolstoy and Edith Wharton. I'm disappointed that I can't find a complete Proust.
Karl Pyrdum, of Got Medieval is delighted by the Kindle screensaver from the Lindisfarne Gospels and may augment it with another 24 medieval images. I hope he does.