
Pidgin is a great GTK2-based instant messenger application that supports a bevy of protocols, including ICQ, Yahoo!, MSN, Jabber, and AIM. It's a terrific app in its own right, but when you add some of these power tools, Pidgin is even better.
pidgin-hotkeys - Use this plugin to assign global hotkeys to quickly perform regular tasks like fetching messages, toggling the buddy list, or opening the preferences pane. Also available in German and Swedish.