Messenger transmits all you convos in plain text. Anyone can spy you. Are you worried about that?
This is a plugin to encode messages before they are sent to the net and to decode them once arrived to your contact. I've just made it. Please test it and tell me what you think.
I've made it in VB so you'll have to follow some easy steps to install the plugin. Read the readme.txt file included in the zip. I'm planing doing an installer, but atm i haven't got much time.
I think there isn't much more to say. Just enjoy it.
BTW, future versions will probably include advanced features like the use of private and public keys, the ability of remember keys etc...