Why and how should CEOs use Twitter? That was the focus of my conversation with Michael Castner yesterday, on the Wall Street Journal’s Daily Wrap. You can listen to that interview below, or read the Wall Street Journal story we were riffing off: Better Leadership with Social Media. In it, I present six ways busy execs can use social media to make their work easier and more effective — instead of seeing social media as one more thing on a crowded plate.