FBReader, an e-book reader for Linux and Windows, has added the ability to download e-books directly from Feedbooks. You can read about the details at the FBReader site here.
I tried FBReader when I was using my Nokia internet tablet, but I found it very difficult to use. I haven’t used a recent version, however. I’m constantly amazed about how much time and effort is being put into the e-book community – all done by volunteers.