If social media is about starting conversations, why not hire the best conversation starter you can find? That explains, at least in part, what Web hosting and cloud computing vendor Rackspace did earlier this year when it hired Robert Scoble and gave the infamous, conversation-starting, high-tech gadfly his own social media playground. That playground is dubbed building43 (after famous, secretive buildings at Microsoft and Google known for their creative output), but whatever you want to call it, building43 is an intriguing experiment in tech marketing—or, rather, nonmarketing.