While this might be second-nature to some, Apple doesn't tell you how to take a screenshot out of the box. So, not everyone may yet know that they can capture their iPhone — or iPad or iPod touch — screen content with just the touch of a button (well, two buttons actually).
To take a screenshot with your iPhone or iPod Touch, just press the Home and Sleep buttons at the same time. If you nail the timing, the screen will flash and you'll hear the same camera shutter sound that the Camera app makes when you take a photo.
To access and share your screenshots go to Photos and open the Camera Roll. (Note: Images updated to reflect iOS 7.)
Here's a video showing all the screen capture steps: