Speaking of this, here's a thought.
Now, I know that the front seat is the least safe place from a crash perspective. But, if the kid is in the back seat, aren't you more likely to be looking back there to check on him, let him see your face if he's crying, etc? Doesn't putting him in the front seat decrease your chance of getting into an accident in the first place?
Just a thought from this kid-less person.