Using iphone 4 As Mobile CCTV

We have the SDK; XCode.

We have the camera + LED.

Just how long can the battery last ?

--> 10 hours of video playback. Refer to the spec.

Has someone done it before ?

Yup. Definitely not a new idea.

I want to put in on my car, to capture who scratched my car.

With 32G of flash drive, it is enough to store enough video.

The problem is still the battery, unless you want to hook it to the car battery and how to have a 360 degree surveillance coverage ?