Who can sit still, especially in a meeting? The only times I don't fidget around and change positions is when I simply fall asleep.
I guess I'm not alone, because Steelcase just developed a chair meant for the questionable posture practiced in meeting rooms. After taking a test-sit, I can say that the Cobi, coming out in February for $635, will support you just fine if you sit up with a straight back and feet on the floor. But it holds you well in just about any other position, too.