Originally Posted by HalfMoon
Samsung added it in the Galaxy Tab (which surprised me when I found out). On the Galaxy tab if you hold the back button and press the power button you get a screenshot, no root needed.
Correct, it was a Samsung add-on, not in the base OS.
Don't get me wrong, I think it would be a great thing for google to just throw in there and obviously it is very doable, and I do not know why it is not just part of the OS already.