I just set up my eight year old son with his own blog. He chose the name himself which I'm kinda proud of.
We're exploring the method (or un-method) of unschooling. I think having him create a blog is a great way to teach him writing, photo editing, computer programs, and photography. I think getting comments would encourage him to share about our homeschool adventures and help with retention. Perhaps, also show others how homeschooling (or unschooling) is working for our family and how the child is directly affected. Especially, as his writing and content improve.
He's very excited about it so far. And so am I.