If you have the misfortune of losing your phone, it's unlikely that you'll get it back. Even if someone wants to return it, password protection will keep them from accessing a number to reach you. With Android 4.1, 4.2 and 4.3 (Jelly Bean), you can display your contact information on the lock screen to increase the chances of reuniting with a lost device. From Settings, go to Security > Screen security > Owner info. You can enter your name, email address, phone number or other information to appear on the lock screen.