Fastest way to get to camera in iOS? There are a few different states an iOS device might be in when one wants to capture a memory really fast:


Power off, with a PIN or password screen
Power off, no PIN or password, but need to "slide to unlock"
Power on - on springboard (no app running, looking at app icons)
Power on - in an app


In earlier versions of iOS one could double click the home button twice from nearly any situation and open the camera.  It appears that there is no quick hardware way built in to the latest versions of iOS, though there is a jailbreak way to enable faster hardware access to the camera.  I'm not interested in jailbreaking, though, so I'm hoping to catalog the various methods one can get into the camera app quickly.

Any tips for making this faster in non-jailbroken devices (such as specific apps that are faster, or placing the camera app of choice in the bottom app bar on springboard) would also be welcome.

How quickly can we get the camera to snap a picture?
If you are using iOS 6 (which I am, I can't get iOS 7 on an iPod 4) and the power is on, no matter what you're doing, the easiest way I found was to press the sleep button to put it on standby, press it again to turn it on, find the little camera icon that's next to the "slide to unlock" bar, drag it up to open the camera, and capture your moment. 

Of course, this answer is very conditional: it only works if you have iOS 6, the device is either on or on standby, and you do not have a passcode (if you have a passcode, it makes you type it in before you can use the camera). But it works for me all the time, and I think this would work pretty well for others, too.