I like the fact that Moodle Blogs don't allow comments.

However, there is also a need for a blog-like activity for students that allows comments from other students.

If students could each have one forum that only they could post to, but which allowed replies by other students, then this need would be fulfilled. The editing time limit in forums is ideal, too, since a student would not be able to change his/her posting after other students started making comments (leaving replies).

Perhaps a list similar to the Participants list could be created that listed all such "personal forums" of students in any given class. (Also allowing sorting by number of replies would be a cool addition.)