Jetico BCTextEncoder - Jetico BCTextEncoder is software that ensures your text-based communications are safe by allowing you to encrypt them.
TheLetterEncrypter - TheLetterEncrypter is a small (14KB download) AES-based text-encryption program.
GNUPGK - A GnuPG Frontend GUI made in C#.
SecretPad - SecretPad is software that encrypts your plain text into a form that cannot be understood by anyone.
GizmoMarks - GizmoMarks is software that provides secure block-notes by encrypting them in a way that nobody can understand.
PlainText Crypto - PlainText Crypto is software that can encrypt or decrypt all your files in plain text.