Many Telepathy UI's for the GNOME desktop are currently under development. This page discusses only one!
Screenshots
Here are a few screenshots to entice you to try it out.
http://adam.uwcs.co.uk/ConversationWindow.png http://adam.uwcs.co.uk/ContactWindow.png http://adam.uwcs.co.uk/AccountWindow.png
Installation
In order to build Chatter you will need:
dbus-sharp (http://www.ndesk.org/DBusSharp)
telepathy-sharp (http://git.ndesk.org/?p=telepathy-sharp;a=summary)
Then download chatter (http://repo.or.cz/w/chatter.git) and a simple make; ./Phone.exe should get you up and running.
Make sure you have the gabble connection manager installed and then set up an account as in the screenshot above.
Development
I'm not really spending time developing chatter, if you want to put some time into it then I would be very happy to accept your changes into the main git repository.