I was lecturing at a university in London today and one of the students called me "sir". I don't actively encourage this, but it's always nice when it happens. (Normally it's only Mrs W and the mini-Ws that use this particular form of address.)
That last bit was a joke, btw.
Old-fashioned US TV programmes are full of kids calling their parents "sir" and "ma'am". On Little House on the Prairie, Laura and Mary would call their dad "Pa", but if he got cross, they'd have to speak to him more formally. Seems kind of appropriate.
Let me just check whether the mini-Ws have done their chores today. There's firewood needs a choppin' and water a fetchin' from the well.