ReclaimPrivacy.org has a handy bookmarklet that shows which potentially insecure and privacy-invading settings are enabled on your Facebook account when you click it.

ReclaimPrivacy’s bookmarklet focuses on just a few key areas where Facebook can share information with the public—having your contacts, connections, and tagged photos exposed to the public, as well as allowing your friends to accidentally expose that information themselves. It also looks at your relationship with Facebook’s personalization, applications, and other aspects to see what Facebook and independent developers can find out about you, then rates your exposure level in simple Good, Caution, or Insecure levels, along with offering links to change those settings.

ReclaimPrivacy Bookmarklet Rates Your Facebook Exposure Levels.