How to take photos of the screen on an iPhone?

I recently got an iPhone 4S, and I really love my new phone! Earlier today, I was going through my pictures when I found a picture of my home screen. I have no clue how I took a photo of my home screen though, and I would like to know how to do this again.

Click the home and power button together and youll see your screen sort of flash. Thats about it.

By pressing the home button at the bottom and the lock button at the top at the same time. Hope this helps.

Press the top button and the home button (on the bottom of the screen with the square in it) at the same time.

You just click the home button and the power button at the same time.

Home screen + Power button together.