[MOSAIC] Blogging Question

[Angela Almond]

I am currently trying to find something:  blog, wiki, discussion board, to
use in the classroom next year to replace the reading response journals. 
We are going to a one-to-one classroom where every fourth grader will have
their own laptop and I think this is a great way to incorporate the
technology with something I already do.

However, when I have looked for something (blog, wiki, discussion board)
to use, I keep running into the same problem.  I am hoping you guys can
point me in the right direction.  Let me tell you exactly what I am
looking for:

I want a site that only the students in my class can respond on.  I don't
want just anyone to be able to post on it.  My students don't have e-mail
addresses so the site can't require them to sign up with one.  It needs to
be somewhat kid-friendly because this is the first year they will have had
access to laptops and many may not have the skills to navigate a
complicated site.  It also needs to be free because, although I love my
kids, I just don't have any extra cash I can shell out on this!

I have a call into our technology person in the county office with these
same questions but since the topic had been brought up here, I thought I
would see if any of you have any suggestions.

Thanks in advance!

Angela Hatley Almond
Fourth Grade
East Albemarle Elementary School