This is available in all devices that can support iOS 5.x. Yes you can have it on a nonjailbroken iPhone 4.I have read that 5.01 on iPhone can have the camera function button right next to the slide to unlock bar. Is this available on a iPhone 4 that is not jailbroke?
I tried awhile back didn't happen will check it out! Love that!Also, you can snap a photo using the volumn button rather than touching the screen. More like a regular camera.