How young is too young?

One of the reasons I have not used Web 2.0 tools with my classes is that I work in an elementary school with grades K-5. I have always used the excuse that these students are too young to be blogging - that their writing skills are to immature to make good use of a blog or other Web 2.0 site. Another reason is that I find it difficult to assign homework from the computer lab where the students only appear every 8-12 days. Any homework I have assigned seems to be too easily forgotten, even if I have the classroom teacher make the students put it in their assignment book. Lastly, I work in a community where I know there are families without computers at home, albeit fewer and fewer. So you can't really assign a computer project to do at home. Maybe it is just that I am too weary with other issues to take this on with all the attending things to deal with - security, monitoring, access for all students.

As time goes on, I continue to ponder these issues. As to the writing skills,perhaps a wiki where others can help edit the entries would be more appropriate, but I would have to make sure the students understand that part of the process is having others tweak your work. That way we could get the info out and work on the correctness of the grammar and spelling as we go. Maybe there is a dual purpose there.

As far as students having access to a computer, I don't feel I can give up the time in my limited computer classes to have them doing thoughtful writing. It is not really the place for that anyway.

My question is how young is too young to be using these tools with students? Is it simply a matter of teacher monitoring and coordinating or is there really some age below which these tools are inappropriate? HELP!