I see that a lot of you have started blogs. You may be assuming that they're visible to the public, but they're not visible by default. Here's what you do to make your blog visible (or to take it private by inverting the directions).

Display your blog. Click the edit post icon in the upper right.

At the bottom of the blog setup form is a button labelled "Select Categories" (if it says "Select Categories (hide)" skip the next step because categories are already displayed). Click it to display the list of categories.

If the "Anonymous" category is checked, your blog is public. If unchecked, it's visible only to registered members.

(Ignore "Public view" and "Public post". They sound helpful, but in reality they're artifacts of an old experiment and I'll remove them eventually.)

Save the form. Your blog should now be public.