Big Brother Camera Security is an intriguing free app that lets you know if someone is snooping around your iPhone. When you install the app you pick a passcode for your phone, and give it your email address. You'll get a confirming email with a code to validate it's you setting up the app, and once confirmation is complete you're ready to go.
Once the app has been launched, anyone who picks up your iPhone is asked to enter the passcode. If they fail to enter the correct passcode, the camera takes their picture using the front-facing camera. They get another try, and the app takes another photo. Big Brother Camera Security instantly emails you both the photo and the location of your phone.
It's a bit like
