I absolutely love Gaim, but the message to group feature isn't readily available, even with gaim2-beta3, and this doesn't work for me especially that I sometimes need to broadcast messages to team members over IM. Quick googling led me to Frank Spychalski's very good article, which covers the essentials of configuring Google Talk on Kopete. For Ubuntu users, if you don't have Kopete yet, you will need an internet connection to get the necessary packages.
$ sudo apt-get install -y kopete qca-tls
qca-tls package will ensure that you'll be able to connect using the default encryption protocol. After these packages install, start Kopete, and create a new Jabber account if you don't have it yet. On the first tab, set up your Jabber ID to use your Gmail address:
On the "Connection" tab, use
Jabber Id: <yourid>@gmail.com
talk.google.com as your server and tick all the boxes like so:
[x] Use protocol encryption (SSL)Done!
[x] Allow plain-text password authentication
[x] Override default server information
Server: [talk.google.com] Port: