The June 2005 issue of Harvard Business Review has an interesting article by Tiziana Casciaro and Miguel Sousa Lobo (what a name!) on informal office networking. They point to one of management's greatest challenges as "the natural tension inherent in every organization" - the problem of convincing employees with different skill sets to work together. Too often, organizations create silos - fragmented knowledge centers that don't work together.
It was an interesting article, and I could write much more about it. Luckily, I don't have to, because Bruce Hope did a good job of summarizing the main points - two weeks before me (the story of my life). He also points to an article in The Economist based on the Harvard Business Review article, The Jerk at Work.