useless rules in the sky

How many lives do you think are saved each year by having the airlines make sure their passengers are seated in "an upright and locked position" during takeoff and landing? Based solely on how anal they are about enforcing it I would say thousands.
It’s bad enough they tell me that using my ipod might cause some kind of catastrophic electronic meltdown in the cockpit, which doesn’t exactly boost my confidence in aviation technology by the way, but what's so wrong with me putting my seat back and taking a nap when we take off? If the person behind me hits his head on the back of my seat because the pilot decides to be funny and slam on the breaks midway through building of speed for the take off, then that person should be reprimanded for not wearing his seat belt, and for being a moron.
And why the hell is it only during takeoff or landing? That's the annoying part. Did Steve Jobs program ipods to only send radar scrambling waves during takeoff and landing? If my seat is a deadly weapon, it should be kept up right and locked throughout the whole flight, not just when I’m trying to ignore your in-flight safety instructions.