British publisher Kraken Opus is bundling a special second-generation iPod touch, which it has dubbed the Prince Opus iPod, with its Prince Opus book, a limited-edition, 280-plus page photographic essay of Prince’s 21 Nights tour. The Prince Opus iPod features a custom-colored purple front and home button, Prince’s symbol logo etched onto the rear, and comes pre-loaded with an exclusive 40-minute movie and bonus audio tracks; both the…