I've changed it so you have to enter an email address to be able to enter a comment.  There are three reasons for this.  One, to make it easier to get in touch with you.  Two, to help prevent comment spam (not much of a problem now, but still). 

Three, so all regular commenters will have their comments approved automatically.  That is, if the blog gerbils recognize your email address, they'll let the comment through immediately.  You don't even have to use your real email address — though email addresses are never published on the site — but be sure to use the same one each time so the gerbils don't get confused.