A paragraph at MobileRead forum tells us that Plucker, a popular open source e-book reader, has been ported to Nokia 770, with a screenshot provided.
Plucker was originally started as a Palm OS application to enable the Palm owners to read the e-books and browse collections of HTML files offline, but currently you can find a Plucker viewer for pretty much any popular operating system out there. Sample readings in Plucker format can be downloaded on the official Web site, so one can now enjoy Definition & Reality in the General Theory of Political Economy by Thomas Colignatus in their pajamas, reading, supposedly, on Nokia 770. The e-book reader itself would be a useful addition to the 770 applications family, as, being open, it also provides for some DRM for authors and publishers willing to distribute their works in Plucker format.