The paper analyzes the contemporary organizational restructuring of production and work within firms. We emphasize the shift from a "Tayloristic" organization of work (characterized by significant specialization by tasks) to a "holistic" organization (featuring job rotation, integration of tasks and learning across tasks). We examine four driving forces behind this restructuring process: advances in production technologies promoting technological task complementarities, advances in information technologies promoting informational task complementarities, changes in worker preferences in favor of versatile work, and advances in human capital that make workers more versatile. Our analysis can also help explain the recent widening of wage differentials and disparities in job opportunities, not only between groups with similar characteristics, but also within these groups.