LONDON (AFP) — Beatles legend and famous vegetarian Paul McCartney was joined by John Lennon's widow Yoko Ono Monday to launch an appeal for "meat-free Mondays." McCartney said going vegetarian, even for just one day a week, was good for the environment because of research suggesting it cuts greenhouse gas emissions from the world's livestock population. "I thought this was a great idea. To just reduce your meat intake maybe by one day a week and this would seriously benefit the planet," he told reporters, alongside Ono and a bevy of other stars including Kelly Osbourne and Moby. Lennon's widow...