pep.security - Privacy by Default.
Jetico BCTextEncoder - Jetico BCTextEncoder is software that ensures your text-based communications are safe by allowing you to encrypt them.
GNUPGK - A GnuPG Frontend GUI made in C#.
PGP Tool - PGPTool allows you to encrypt and decrypt files. It's free and easy to use.
GizmoMarks - GizmoMarks is software that provides secure block-notes by encrypting them in a way that nobody can understand.
GPGTools - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.