Detect motion, take pics, upload to email

I have an I-Phone 4. I want to set it up so that it detects motions, takes pics and uploads them to email.

Do I have to buy an app to detect motion or does the I-phone already have this capability? I can write scripts and programs when I know the steps involved.

Ideas? Where should I look?

Surely someone has seen this done or has it on his i-phone.