I also liked the blog that was done in the school. Anyone could read it but only the teacher and here students could post to it. They kept track of good wikis about technology and made their own wikis about technology. awesome.
The other one that was a hub of articles about all things library was really cool too. I liked that anyone could post. What a powerful tool to have at your fingertips! Why reinvent the wheel all the time, learn from others experiences and modify and adapt to the situation you are in. Do what you are able to do.
All of these wikis strike me on one thing. If say, I wanted to find talk to another librarian to try to start a particular program in my library, lets say a gaming program, but I don't know any other librarians that are currently doing that, what do I do. Find a wiki about it. It provides instant connections with people who you would probably never come across otherwise because it is just regular people putting out what they have done. It is not necessarily "published" but it is none the less available. What an amazing tool!