For fans of HD and / or nature documentaries, the BBC Planet Earth series is the unquestioned champion, and to provide a proper followup the Brits are improving it the only way they know how: doing it live. What the broadcaster calls its "most ambitions global wildlife series ever" will air simultaneously in 140 countries (more on that bit later) starting Sunday May 6th, then every Thursday and Sunday for three weeks. The plan is to track animals in seven different locations around the world in real time as they struggle for survival and broadcast it all in HD. One segment features Top Gear's Richard Hammond following a