As Madonna bounds on to the huge Wembley stage to save the planet, how the assembled Greenies will cheer. The superstar is today fronting the massive Live Earth event, with nine concerts played over 24 hours across seven continents before an audience of two billion. The much-hyped bid to save the world is being masterminded by former U.S. vice president Al Gore - who helped focus attention on the environmental movement with his Oscar-winning film, An Inconvenient Truth - and features artists including The Police, Red Hot Chili Peppers, UB40 and Metallica. No doubt to rapturous applause, Madonna will call...