This site is powered by Drupal for Facebook.
The page you see here is also visible in a facebook application.
I authorized during the tour. How do I remove authorization? There's now clear way.
I believe Facebook has introduced a way for an application to do this, but we haven't caught up with that yet.
So just go to http://www.facebook.com/settings/?tab=privacy, click the settings link next to applications. You'll see this app on the list and you can revoke privileges from there.
If you ever re-authorize, your account here will be reinstated.