Just the other day, I managed to take a screenshot on my iPhone, and only realised when I browsed to my Camera Roll and saw the home screen.
Anyway, to take a screenshot, press and hold the ‘Home’ button and then pressing the Sleep/Wake button.
It seems to work on pretty much any area, such as Apps, iPod and video playback. Give it a try. 🙂
And now, for no reason other than to decorate this rather spartan post, are some screenshots that I’ve taken.