First, password protect your phone and lock it. Then slide to unlock and do this:

1. Tap emergency call.
2. Double tap the home button.
Done.

You are now in your favorites. This seems like a feature, because you may want to have emergency number in your favorites for quick dial. The security problem here is double. The first: anyone picking up your phone can make a call to anyone in your favorites. On top of that, this also opens access to your full Address Book, the dial keypad, and your voice mail.

Full story:
http://gizmodo.com/5042332/huge-iphone-security-flaw...