ScrapBook - ScrapBook is a note-taking application for Palm OS that helps you manage a large collection of notes.
You can organize your notes in a hierarchical collection of folders, with unlimited nesting depth (in addition to organizing by standard Palm OS categories). Flexible search capabilities help you find the note(s) you're looking for.

ScrapBook supports encryption, using the DES algorithm. You can choose which notes to encrypt, and what password to use for each encrypted note.

ScrapBook runs on Palm OS version 3.5 or higher
Requires 107kb of RAM for the program + additional RAM for user data
Distributed as .zip format compressed archive, containing ScrapBook.prc + documentation

ScrapBook is shareware with a 30-day trial period; it becomes fully functional when registered.

Features include: Nested folders, categories, keyword lists, multiple keyword search, multiple string search, encryption, internal cross referencing (for speed), and import/export from Memos.

The .zip file includes a complete user's manual.