At my place of employment, my department has recently decided to undergo a '2.0' revamping. As a part of that, they decided that they wanted to use internet technologies to increase communication between departments, and between management and the masses of peons. Somebody got the bright idea to build a wiki and use that to disseminate information throughout the organization.
They never told anybody what the URL for the wiki was, and to this day, there is no structure to inform interested parties that there is information posted which is meaningful to them. My boss chewed me out because I hadn't read a post she put in a wiki I had never heard of but was somehow expected to be aware of and monitoring constantly.
I knew it had hit critical mass when I saw that somebody had created a facebook group for my department. Once again, without provocation, and with no formal announcement. I wouldn't want to mix my personal life with work as it is, so I would never join such a thing.
People like to throw around buzz-words like wiki and 'web 2.0' and social networking and think that if they build a website around these ideas it must equal greatness. I was reading the other day about how people don't understand what Twitter is and how to use it. Most people using it think it's like a game, and that the more people following you, the 'more powerful' you are. I think my department has fallen into the same mentality that more must be better. They've got no less than 4 wikis with the same information, and no structure to let anyone know about updates.
What can we learn from this example? Simply put, in this day and age, I think that less is actually more. Wikis and Facebook groups, and twitter are wonderful, but only if they are used in moderation, and used correctly. The wiki is a good idea. Organizations, schools, clubs, and pretty much any other organized group can benefit from a central repository for knowledge. However, it's only as good as the contributors. If only a small group are aware of the knowledge management system, then not everybody can contribute, and the information doesn't get out.
Personally, I prefer my bosses just sending out a blanket email to everybody like they used to do back in the 90's.