Handy instructions shamelessly lifted from Derik and Lisa's lovely blog
Step 1: Click on the words at the bottom of the post that read "# Comments"
Step 2: Type your comment into the box that reads "Leave your Comment"
Step 3: Select your identity from the "Choose Identity" radio buttons
Step 4: Fill in the funky word in the box.
Step 5: Click the "Publish" button.
We love comments.