Interesting so many comments about time. I *think* the source of the "only while playing" rule has to do with this focus on how much time a kid is spending watching TV... I think those parents somehow think it counts less if the kid is doing something else at the same time. Others have talked about using it as a way to get time off direct childcare.
I don't know how much time my older son spends watching TV. I know it's more than most people here describe. I've specifically stopped timing it and started focusing more on the hows and whys and whens. About 75% of his tv time is spent with both of us watching and not doing anything else, which I think is very rare...
We've had a specific problem which involved a kid who really can't entertain himself very well without 1 on 1 attention... and I've actually been using TV time sometimes to prepare things to help him LEARN to entertain himself (stuff that's just in his incredibly minuscule zone of proximal development, is my theory)
What rules do you guys make around the *quality* of TV time?