Longtime Yahoo exec Brad Garlinghouse's appointment to a new job at AOL today is yet another sign of an interesting trend for those keeping score of the comings and goings of top Internet execs. As anyone who watches the digital space knows by now, this kind of management musical chairs is common and never-ending, although it seems more frantic than ever of late.In fact, borrowing from a quote by IAC/InterActiveCorp Barry Diller quote from an onstage interview I did with him at the sixth D: All Things Digital, and switching out Hollywood for Silicon Valley: " is a community that's so inbred, it's a wonder the children have any teeth."