James, in the book menu, you can also hit the "Option" button and change the Sort Order from the context menu. If you choose the "Most recent" option, the menu lists your most-recently-accessed book at the top, the second-most next, and so on down the list.
Just a thought. This machine runs linux. Has anyone thought of making the root of the SD card a symlink under the Books folder? I would, but I haven't a SD card lying around, and I've still got about 1,75 GB of the base memory available.
I don't know Linux, so I certainly haven't. But if anyone does, I'd be very interested to hear how.