Project Gutenberg (external) is a library of gratis ebooks. These are mostly books on which copyright has expired. They are now part of the public domain.
Distributed Proofreaders (external) is a companion site that aims to make it very easy for anyone with a reasonably fast internet connection (and a browser that supports cookies and JavaScript) to help produce these books for Project Gutenberg.
Currently, OCR technology has come so far along that it is practically usable for producing quality text from scans. However, littered throughout these etexts are still dozens of small mistakes. To help catch and remove these, Distributed Proofreaders was set up.
In August 2003, I bought myself a Palm Zire PDA to read the texts I had helped produce, and some of the classics. Unfortunately, my first search on Google for free ebooks for the Palm Pilot was rather unsuccessful. All the links I found led to publishers of commercial ebooks who used some freebies as teasers. Project Gutenberg does provide free ebooks, but not in a Palm native format.
I have made a page to help you find free ebooks for your Palm PDA.