I discovered that there is a way to do this without a charge (I can mail a .txt or .html file [other formats, too] to a email@example.com address. The Mother Ship converts the file to .amz format and sends it back to me).
I didn't RTFM closely enough to discover this right away (RTFM is the technical support term for "Read The F* Manual"). So ... I remain impressed by this device. There are a couple of little ergonomic features I'd change, but overall, I like it a lot.
Now the question is: What do I do with all my other gadgets? I've got a NEC 800, a NEC 790, a REB, an ebookwise, a Tungsten, a Palm, 3 laptops, and a Nintendo DS. I use all of them to read ebooks (and do other things, like write). Should I retire them? Or have a fire sale on Ebay?