Google has just released a beta version of their instant messaging service called Google Talk. Users dont have to use their IM client for logging in to the service. They can use any jabber compatible client like gaim and start chatting. They will not be able to use the voice chat feature of the service, though, if they use anything other than the official google client.
Dont be surprised if you see advertisements popping up on the screen in the middle of your conversation ;) Suppose you are chatting with a friend about foreign travel and google starts showing you travels ads, you are bound to be tempted enough to click on one of them. And help google make more money !! Sound like microsoft to me !!