In Will Richardson's book Blogs, Wikis, Podcasts and Other Powerful Tools for Classrooms, he defines a difference between a blog and a journal/ A blog should contain reference to other material on the web, on which it should either make a comment or form some sort of synthesis. If the entry is totally self-contained and only provides a personal view of some concept then it is a journal entry and not a blog.
I take a more pragmatic view that a blog will be a mixture of both as you often need to create the context for your blog and you do this by putting in the personal - journal entries. I have done this here.
There is one way of cheating, and that is to also write the links that you refer to!
I have been working on wikipedia and writing an article on Student Approaches to Learning. It is a good way for me to practise what I preach and to see the effect of wikis on learning as I am learning within the DipLaTHE.