This was featured on "Free Technology for Teachers" Blog as a website that requires no registration. You just start blogging and you can make your post public or private. Could be great for the under 13 group.
Enokson has created for us a kind of road map containing all the major critical thinking skills we need to know about. He put these skills into an image that you can download from Flicker. I have, however, took his image and turned it into an infographic-like embeddable HTML code to use on your website or blog. Check the code below if you want to embed it on your blog but please if you are to use this link anywhere else online make sure to pay credit to Enokson.