JitBit Enkodr is the world's easiest "on-the-fly" text encryption software. It works in conjunction with ANY text-editing program: MS Word, MS Outlook or even a web-based email like GoogleMail or Yahoo.
(1) Encrypt some text using a key
(2) Send this text to a friend and tell him the key.
All you have to do to encrypt (or decrypt) some text is: (1) Select the text with your mouse (2) Press Ctrl+Shift+F9 on your keyboard (3) Enter a "key" phrase (a password used to encode/decode the fragment).