There’s that old idea: if you see a bunch of people frantically running in one direction, run with them. They’re probably running from something worth running from — a terrorist attack, Godzilla, the Stay Puft Marshmallow Man… you get the point. That same logic has now been adapted for the digital age, courtesy of a project that treats billionaire travel habits like an early warning system for the end of the world. First noticed by  Boing Boing , developer Kyle McDonald’s “ Apocalypse Early Warning ” site is predicated on the simple, cynical premise that if a catastrophe is looming, the rich will know first and flee immediately, like the cowards they are. They’ll get on their private jets and haul tail to their personal quaint and quiet private islands or whatever.…