Good am,
I was reading about a recently announced bug that I can confirm works on the iPhone software 2.0.1 and 2.0.2. The bug allows someone to access your phone even if it is locked. To test your phone do this: 1. Lock your phone, 2. hit the slider, and then press the emergency button then press your home button twice.
If it takes you to your favorites, your experiencing the bug. By selecting the users there, and hitting the blue arror next to their names, someone could access addresses, email link (which will launch the email app), text people, etc.
THE SOLUTION:
Unlock your phone and go to Settings > General > Home Button (scroll down) and then change the functionality from Favorites to "Home".
Now go back and try to reproduce the bug. It will not just go back to the locked screen.
Thanks to "hypnocat" in the Macworld forum for sharing this.