IM in your Linux Distro

Google any IM client for Linux. E.g., http://pidgin.im/ which I am using on my Fedora codre 8.

Download pidgin and save it in /etc/yum.repos.d/
Then Run the installation

$ yum install pidgin

This should help.

To confgure the pidgin for google talk,
the following link may be useful
http://www.google.com/support/talk/bin/answer.py?answer=24073