Every time you lay down, you have to turn off auto rotate, or else your phone will go into landscape when you’re trying to read it. With a rotation notification toggle, it’s not all that inconvenient, but it could be so much easier. Samsung understands that, and debuted a new feature on the Galaxy Note II called Smart Rotation. Just like Smart Stay, it uses the front facing camera to track your face. The phone will rotate based on the position of your face. So if you’re laying down, but it sees your face right side up, it will not rotate.
This is an awesome feature, solving a big first world problem will smartphones. It might drain battery slightly faster than the accelerometer would (an educated guess), but I think it’s worth the tradeoff. Samsung, good on you for thinking of the user who’s too lazy to switch off auto rotation.