In order to post a message, click the header above that says "Want to post a message". Then use the comment section that will appear below this post. Your message will be reviewed and posted by the moderator. You know, assuming it isn't spam or something!
Alternately, you can email Dan your message. See the contact page for how to contact him. Sure, I could just tell you here, but if you've got something interesting to say, it's worth the extra couple of seconds to click another link. Oh, and bend your knees!