Skype was very close to buying out a VoIP firm called Gizmo5. Since Skype ended up passing, Google moved on in according to a rumor. Gizmo5 was founded by Michael Robertson. The company uses the the Session Initiation Protocol (SIP) and Extensible Messaging and Presence Protocol (XMPP) for VoIP communication.
Google will be spending roughly $30 million in cash on the deal according to TechCrunch. It is likely that Gizmo5 would be rolled into Google Talk. Gizmo5 started in April 2003 and raised about $6 million in total funding. Before starting Gizmo5, Robertson founded MP3.com and MP3tunes.