Taking Screenshots on your iPhone
Guess, what?
Apple has a built in way of taking a screenshot on your iPhone. (Which explains how I’ve inadvertently gotten a screenshot in the past.)
Hold down the Home button and the sleep/power button on the top of the phone for 1 second. (Keep in mind that holding down this button combination for 10 seconds can cause the phone to reset. Also this requires a 3G or newer iPhone running iPhone OS 2.x+.)