Word on the street is that Michael Robertson has been shopping SipPhone. You have to realize he builds companies to sell them after developing rock solid technology.
If you look at Yahoo, especially in the software on the desktop and laptop space, they have been very PC centric, where Robertson and crew have been very Linux and Mac aware. If there is one Mac client in VoIP sector that rocks its Gizmo, as it is far and away the best client I've used for Voice, including Skype and EyeBeam on the Mac.
Given that SipPhone/Gizmo alum Jeff Bonforte already being at Yahoo, the apple wouldn't have to fall far from the tree to be a great fit.
But let's go beyond the softclient and look at why this makes sense. It's called the college market. Already SipPhone has embedded SIP servers in the University of California campuses across the state. That means students can make free direct dial calls to one another and home using Gizmo and Gizmo out. They can add a Gizmo In number as well.
The college audience is hot right now. FaceBook is one of the hottest companies in the sector, and MySpace was bought by News Corp. for the same reasons. With an already proven college campus penetration model on the technology side of the fence, Robertson has shown his guerilla marketing smarts. Besides he's already onto his next play with MP3Tunes.com so this is the ideal time for Golden Boy to sell SipPhone and give it a home where his vision and ideals can be carried on.