We really do need a secure, distributed, anonymous, yet cost ineffective (ie, too expensive to spam) communication system.
send a message to a bitcoin address the same way you might send a payment.. (though likely using a different method :p) Might be worth poking at Namecoin as a plugin for it.
Ladies and gentlement may I present to you..... Retroshare.
A crypto friend to friend, p2p, distributed instant chat, forums and filesharing.
http://retroshare.sourceforge.net/
Whole thing uses gpg.
Awesome! Thank you very much for sharing this. I think RetroShare seems to be a great project. I will give it a serious try imminently.