Mari Anderson is a writer who, when not typing, can frequently be found with a sketch book. In a yoga pose. In a personality test given to volunteers applying to become Big Sisters (www.bigbrothersbigsisters.org), she scored alarmingly high in the "adventuresome" and "risk-taking" categories. Which may help explain why, at age 45, she sold a perfectly nice graphic design biz to sail off to a remote island in the Bahamas with a guy she'd been married to for a week. Besides co-authoring Plunge, Mari is a registered yoga teacher who prefers to think of staring at a blank page as meditation, not w...