If your site is listed here and you wish it removed, you can use the contact form.
Simply fill in your information and select "Remove My Site" from the category drop-down list (that part's important - it appends "Remove" the the email it sends so I know what it is.) In the Message field, enter the url of the page you want removed, or the name of the site. (The page url is preferred.)
Please give me a day or so to get it removed.