Ok, I have installed Google talk and also have bunch of friends online.
The good thing is that it is based on open protocol Jabber/XMPP. So I don't need any special client for Linux, Gaim just works fine.
The drawback - Google has not released Linux client :-(. So no voice chat from Linux. If Google want to compete with Skype with thier P2P voice technology, they better release Linux client. Otherwise it is just "Yet Another Instant Messenger" for folks like me.
Now I have four services configured in Gaim - Yahoo, MSN, AOL and Google Talk.