It may not be the default chat client in Ubuntu any longer, but Pidgin is still an awesome application. Below are 5 tweaks and plugin’s i install off-the-bat when i’m faced with a fresh version of Pidgin.
Pidgin Facebook Chat
Chat to Facebook contacts from within Pidgin and see available contacts sat amongst the rest of your pidgin contacts.

Download
Open a terminal session and type

• sudo apt-get install pidgin-facebookchat

Or download the latest .deb from the official project page @ http://code.google.com/p/pidgin-facebookchat/

MusicTracker is a “now playing” plug-in for Pidgin. It supports a palatable herd of music players, from Banshee to LastFm and provides a wide range of customization options (such as format, when to show, etc.)

Open a terminal

• sudo apt-get install pidgin-musictracker

Configure via the plug-ins menu.
Auto-resize Buddy List
Auto-resize does what its name implies: it automatically adjust the height of pidgin to fit the number of contacts in the buddy list. Particularly useful if you only choose to show currently on-line contacts.

Download
Deb available @ http://raoulito.info/plugins/pidgin_autoresize/
Avatars To The Left
Display contacts avatars on the left of the screen with this tweaked theme.

Download