Encryption

ABC CHAOS
A program which is able to encrypt and decrypt files of every type and even whole directory structures using strong encryption.
http://www.safechaos.com/abc.htm

AES Free
Creates self-extracting AES-encrypted files for Windows
http://www.abensoft.com/free.htm

BitCrypt Free
A tool allowing for encryption of plain text within a bitmap image. [Win32]
http://www.geocities.com/moshe_szweizer/

Chaos Mash
Offers 30 different way to encrypt a file along with personalized key for decrypting it.
http://www.elgorithms.com/downloads/chaosmash.php

Cif-Crypto and BlowCif
A small freeware "live-text" encryption tool for Windows platforms.
http://maicuin.com.ar/cif

Crypto Anywhere - OpenPGP Edition
Allows for secure email encryption on the move, and can run from floppy or USB drive.
http://www.bytefusion.com/products/ens/cryptoanywhere/whatiscryptoanywhere.htm

Cryptomathic File2File
A password based file encryption solution for the Windows platform. It is free for private use.
http://www.cryptomathic.com/file2file/

DataRescue
The aCrypt software allows the user to encrypt files and send them via email to others without the software.
http://www.acrypt.com/

FineCrypt
Multiple ciphers and key manager integrated with the Windows shell.
http://www.finecrypt.net/

Iron Key
Encrypts files using the industry-standard DES cipher and produces self-extracting Windows executable encrypted files, which can be sent safely over the Internet.
http://www.bestcrypto.com/products/ikey/index.php

Recommended Tested Free Encryption Software
A collection of software that has been extensively tested, probed and scrutinised for weaknesses by a group of security experts.
http://www.angelfire.com/ct3/encryption/

ROT-13 Encryptor & Decryptor
Web form to encode and decode ROT13, a simple letter substitution encryption scheme.
http://decode.org/

Secure Hive Freeware
Encrypts files for archiving and sharing of parts of, or entire documents.
http://www.securehive.com

SecureTask
Professional task manager which allows for automatically performing various security-related tasks, such as automatic encryption, wiping, and system cleanup.
http://securetask.net

4t HIT Mail Privacy Lite
Sends and receives private data hidden in images of various types by using a strong encrypting algorithm.
http://www.4t-niagara.com/hitmail.html

TrueCrypt
Open-source free on-the-fly disk encryption for Windows XP/2000. It can encrypt partitions or create virtual encrypted disks within files. Implemented ciphers: AES-256, Blowfish (448-bit key), 3DES, Serpent, Twofish. Provides plausible deniability.
http://www.truecrypt.org/