I found a couple interesting titles but they are both in djvu, with no apparent way to translate. I guess Nook can't handle that. There is a Sumatra reader but it seems to be windows only. By the way, I have a new problem, yay. I was looking at a "book" and the pages disappeared. I could make them reappear but they vanished again, and fast. I have no idea how to fix that. It's happened with two of them.