I'm not sure if this has been brought up yet but it has been around for a while on Willis Street in Wellington. One of their BNZ ATM units has a sign saying that it dispenses Australian money as well as New Zealand money.
Why is this?
As far as I know Australian dollars are no good to merchants in New Zealand and money can be changed at most airports and banks.
I'm probably missing a big piece of the pie but it seems silly to me.