Howtoforge posted an article about protecting file with TrueCrypt 5.1a on Debian Etch

This document describes how to set up TrueCrypt 5.1a on Debian Etch (GNOME). Taken from the TrueCrypt page: "TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device). On-the-fly encryption means that data are automatically encrypted or decrypted right before they are loaded or saved, without any user intervention. No data stored on an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. Entire file system is encrypted (e.g., file names, folder names, contents of every file, free space, meta data, etc).

Protect Your Files With TrueCrypt 5.1a On Debian Etch (GNOME)