[mverwijs]

Hardly solved. I want it to be so simple the average Facebook user will want to use it.

Emacs hardly fits that bill. Nor does popping up any other editor I think.

I would just like to use the native browser interface and right before doing a POST, have the browser do a pop up and ask me which of my friends I would like to share the text with.

[mverwijs]

Also, there is the decription part. The browser would need to auto-decrypt on the fly all the encrypted messages that are meant for your eyes only. Without asking for a password every time. And without having to open a new application. Rendering pages might prove difficult, as the page can only be rendered properly after decription.