Facebook is testing a couple new features in the security department. One of the features will give a few of your most trusted friends to the ability to unlock your Facebook account, and the other lets you to use a password to access third-party applications.
The trusted friends feature could be useful if you ever find yourself locked out of your Facebook account for whatever reason. You’ll be able to select between three to five of your best friends to provide you with a spare key of sorts into your account. Facebook will send these friends access codes that they will give to you to get back into your Facebook account.
The second feature is application-specific passwords. Instead of logging in to a third-party app using your Facebook credentials, you can generate a random password that is good for that single application. The generated password will need to be used in conjunction with your Facebook email address.
Via [Facebook Blog]