I've been thinking on this too.
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.

now do you have a plugin for pidgin? :p

i think you missed the point... OTR is terrible for one. if it fails, it just unencrypts the message and sends it... about as secure as a shoebox :p and I would have it fail very frequently..
And I wasnt talking about simply encryping an existing IM, nor do I even really want an IM feature.
I was talking about a distributed p2p and innately encrypted replacement for email. A random new IM client to run is hardly helpful for that, and since it doesnt plugin to pidgin I'd likely never use it. (I only use aggregate IM clients.. and grudgingly skype.. if some one ported the skype protocol and made a plugin for pidgin and trillian, id jump for joy )

What i'd rather see is small messages during a transaction. Like sending BTC to someone and adding a small note or something.

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.