I found FCW.com's article on tacit knowledge especially interesting in light of an experience I had yesterday at DCI's Enterprise Portals and Web Services conference. The article points up how so much knowledge is locked into people's minds and never captured via information systems. This is one of the key aims of collaboration systems, but you may want to think broadly about who is a part of that community. At the DCI conference American Airlines was showing off their employee portal, which included an attractive section for retirees and former employees containing benefits info and the like, but no collaboration features. Who better to get involved in the knowledge chain than people who know all the tricks of the trade...?