The free TX2PH site provides e-books for WAP-enabled phones and PDAs.
You can choose from dozens of Gutenberg books.
Or ask site operator Dmitri Svetlanov to add a new title (a short text you provide, or another book).
Reminder: This and other services are laudable. At the same time, remember that your phone company may still charge you one way or another—imposing a data fee, for example.