Crypub is a project mainly written in ..., it's free.
messing with crypto and pubnub
git clone git://github.com/stephenlb/crypub.gitIn Chrome, Safari or Firefox open:
file:///__PATH-TO-CRYPUB__/aes-chat.html#MY-PASSWORD-HEREReplace "MY-PASSWORD-HERE" with your secret password.
Finally Open the same URL in another browser window to communicate in secret with yourself.
To get a friend to chat, have them follow the same steps above. Make sure the password is the same!