- The Portable Beat Reader by Various
- The Portable Mark Twain (Penguin Classics) by Mark Twain
- The Portable Sixties Reader (Penguin Classics) by Ann Charters
Double-checking that book size rule of thumb, I visited Project Gutenberg for ASCII (plain text) files, MemoWare for various PalmOS e-book formats, and browsed further on Amazon for Adobe Reader and Microsoft Reader formats. Here's some sample data on Charles Dickens' The Pickwick Papers (848 pages in the Penguin Edition)
In summary: compressed formats for the Palm and Microsoft reader are much smaller than straight ASCII and Adobe Reader's format is huge. [How did Microsoft manage to add in the DRM and compress at the same time while Adobe exploded the file?] Multiplying this per page size by the "nearly half a million pages" in the Penguin collection (rounding up to exactly a half million pages), we get total collection size between 0.45 GB - 1.51 GB.
That is portable.
The tricky part now is getting a small device with a sufficiently high resolution screen. I'm watching for the "insanely crisp and clear" e-ink technology used in the Sony Librie to move further into the market.