Google have closely followed their launch of Google Desktop 2 with Google Talk.
And it works.
The Google client also integrates very nicely with an existing gmail account, although any XMPP/Jabber client can connect to the service.
There’s still the odd bug here and there, but yes, somehow Google just knows what people want and when they want it. It even supports basic proxy authentication, which is exactly what I used to struggle with on Skype and others.
Nice Google, rock on.
Don’t become evil.