Well, I visited the local bookstore and they had nothing so I went shopping on the internet. Apparently many of Piper's books have lapsed into the public domain and are available for free at Project Gutenberg. WhoHoo! Score! So I nabbed a few of the zipped .txt files and started reading them on the zipit with greader2x. Not bad, but they're also available in epub format, and some of those come with pictures! I had to have it.
After a tiny bit of research I discovered that epub is really just a zipfile with some xml packaging around html formatted books and/or chapters. Once unzipped it can be read in a browser. I found the ebook-tools C library which I might use someday to add epub support to greader2x. But meanwhile there's epub-read.sh, a simple shell script to unzip, parse, and browse the contents of an epub file.
You can edit the script and replace the call (near the end) to the glinks browser with links for text only epub reading, or with netsurf for something that looks more modern.