Enigmail is an extension to the mail client of Mozilla / Netscape and Mozilla Thunderbird which allows users to access the authentication and encryption features provided by GnuPG
VaultletSuite 2 Go is privacy protecting software that installs on your hard drive or your thumb/USB drive. It uses Open Source 2048 bit RSA public key and 256 AES encryption, and provides easy-to-use (transparent) encrypted and controllable email and password protects important files.
The Gpg4win project aims at updating the Gpg4win Windows installation package with GnuPG encryption tool, associated applications and documentation on a regular basis.
The GNU Privacy Guard (GnuPG) enables people to securely exchange messages and to secure files with both privacy and strong authentication. GnuPG is a free software replacement for the PGP suite of cryptographic software.
Portable Gaim is the versatile Gaim instant messaging client packaged as a portable app, so you can take your IM settings and buddy lists with you. The Off-the-record plugin is also included for secure, encrypted messaging
Portable Thunderbird is the popular Mozilla Thunderbird email client packaged as a portable app, so you can take your email, address book and account settings with you.
TorPark allows users to plug in a small USB adapter and run the program compilation and have a virtual secure and anonymous connection to the internet leaving no tracks behind.
TrueCrypt is a free open source on-the-fly encryption (OTFE) program for Microsoft Windows XP/2000/2003 and Linux. It allows one to create a virtual encrypted disk within a file and then mount it as a real disk