Many edublogs (See Education for Well-being and World without Walls for example) are fond of telling us that learning is now all the network and that the web has become a great open resource that will dramatically improve our ability to educate people. In general, I am in agreement on this matter and share the view that the web is a powerful tool for teaching and learning, but we are still a long way from having the best tools for use in classrooms, especially elementary school classrooms.
The most common criticism of K-12 teachers is that our classrooms are not open to the web and to the resources available there. These classrooms are described as "closed." I am not sure that "traditional" classrooms are as "closed" as these authors' propose. As teachers we have had books for a long time and good teachers have always brought in lots of outside resources (movies, pictures, current events, community members, etc.) to their classrooms. Today they have a new source of material (the web) in which they can bring information and material, but that doesn't mean the classroom was ever a "closed" knowledge space.
The problem with framing the issue as a "network" vs. "closed" system is that we may be ignoring the real issue which is that teachers needs reliable systems of resources that are easily accessible. It is still easier find a useful book for use in your classroom than it is to find an equally useful website when you compare things like credibility, reliability, right level of difficulty, range of activities for your classroom, etc. Yes, you can find this on the web, but it still takes more work. You can google words and find stuff, but most of what you find is not that useful for your classroom or the particular level of your learners. In most cases, it is also up to teachers to judge the credibility of the material that they find on the web. Sometimes this is easy to figure out and sometimes not. (Are always right all the time, of course, not, but at least we know that there has been some editorial review.) Can teachers still find useful stuff, yes, of course, and many are finding it, but we have not paid enough attention to building a robust system that allows teachers to find the right material in easy ways.
It has been assumed that we would build "digital teaching repositories" and there are a few out there, but even these are far less useful to the average teacher.
If we want teachers to use the web, we are going to have to build better tools for them to use.