Writing it down in case I forget it …. #1

Want to take a screenshot on the iPhone and, I assume, the iPad ?

Press the [Lock] and [Home] buttons at the same time … you'll hear a camera shutter click, and see a new picture added to the Camera Roll in the Photo app

For those who may not know, the [Lock] button is the one on the top right-hand edge of the iPhone, to the right of the headphone jack. Similarly, the [Home] button is the one on the bottom of the device, used to switch applications, start Siri etc.

As pictured here on the Apple iPhone S spec page