>What other countries make this list?

I think it has to do with whether or not the countries divide up immigration and customs. If memory serves, in the UK you see an immigration officer first, who just cares whether or not you have the right to enter the country.

The customs officer is the one concerned with how many cigars and bottles of rum you have. If you 'follow the green line' you probably never see the customs officer unless you're picked for a random search.

In places like Canada and the US these roles are mostly combined into one person, so there are more questions. I think these questions are mostly just delaying tactics to see if you start to get nervous or sweat, or to see if the illegal parrot in your carryon starts demanding a cracker.

Cheers,
Geoff Glave
Vancouver, Canada