Sitting still for up to an hour without whinging at me... I can see the benefits to this.

However, I also bought Liebling some games for my DS so I get some quiet time (for working or when he has to be still/quiet). As an adult, sitting still for an hour with nothing to do is very difficult - heck, I invigilated a half-hour test today and was bored out my brain! By all means teach children appropriate behaviour, but IMO provide some stimulation for them while they're sitting still: a book, video, computer game, drawing/writing material... children can sit fairly still and fairly quietly without having to learn how to switch off from life. And without pain too.