They're both rich and famous, they're both notoriously earnest and left-leaning, they both have reputations for being emotionally tortured. So it makes a kind of cosmic sense that Sean Penn and Pearl Jam front man Eddie Vedder would be friends; they have been since 1995, when Vedder wrote music for Dead Man Walking, in which Penn starred. Both are currently experiencing second acts, Penn as a director and Vedder as a film composer. The duo have now collaborated: Vedder has written the sound track for Penn's movie Into the Wild, based on the book by Jon Krakauer. Later this month Vedder...