It there's one thing really irritating about leaving your iPhone out with friends, it's when they unlock to unleash all kinds of madness (usually on your Facebook) while your back's turned. You can always use a passcode, but maybe it's time to add an extra step to the "Slide to Unlock" screen, by adding facial recognition.
RecognizeMe is an app aimed at jailbroken iPhones, and basically gives you the option of not just using a passcode to unlock your phone, but to require facial recognition too. After adding a few images into an image