Get This plugin adds private messaging between users, and allow users to receive notfications about new messages, view conversations, reply to other users, It includes nice features such as emoticons, nice ajax notifications, easy conversations and quick-reply.
This is the first release of the addon. If you have any question about it, please submit it in the Private Messaging support forum.
The plugin will be improved, and a lot of options are going to be included based on user feedback and experience.
To test the chat/messaging please login with an account to the UserPro demo, because the messaging feature is only available for registered and logged-in users.
Demo & Source
Download Private Messages for UserPro