As you may have heard, we've released our IM/Voip system Google Talk into beta. Talk uses XMPP for its communications protocol, and the team
has a document outlining
how to use a standard Jabber client to communicate with Google Talk. This makes for a very
nice programmatic interface for IM. There are interfaces in multiple languages, including
Python, PHP, Java and C#, and the Jabber Software Foundation maintains a healthy list
of libraries on their
site. We hope you enjoy our developer-friendly Google Talk.