Just to pick up on the smacking point... less smacking does not means less well behaved kids. Both me and the missus we're smacking by our parents when we were little, when our eldest was born (he's 3) we said that we would smack him if the situation came for it.
He's not a naughty child by any means, in fact we know he's fairly well behaved, but like any kids his age he has his moments when "timeout" etc hasnt worked and he's crossed the line after many warnings, so we've smacked him, no hard, but enough to make the point.
However, when our youngest was born (and after talking to my sis who did similar) we decided to stop smacking completely as we didnt want ewan (youngest) to see us hitting Kristof (oldest). And you know what? Kristofs behviour has actually improved significantly since we stopped smacking. Sure, he's gets the Fergie-hairdryer treatment, but the nearest he gets to physical action is a prod on the belly or a firm hold of the arm and a march off to the corner.
I'm not saying you shouldnt smack kids, but don't say that NOT smacking them makes them more of a problem, because it doesnt.