It's the same here. Well, similar, you're not legally required to carry it with you; most people do so anyway for convenience. But some countries don't have a national id, including but not limited to the US.
The UK briefly introduced and then scrapped a national ID system, bowing to public pressure. Read about it here: http://en.wikipedia.org/wiki/Identity_Cards_Act_2006 -- a key phrase being "Many of the concerns focused on the databases underlying the identity cards rather than the cards themselves."
It's not something you can easily compare across borders and it's extremely loaded with all sorts of issues in the US, as far as I understand.
The UK briefly introduced and then scrapped a national ID system, bowing to public pressure. Read about it here: http://en.wikipedia.org/wiki/Identity_Cards_Act_2006 -- a key phrase being "Many of the concerns focused on the databases underlying the identity cards rather than the cards themselves."
It's not something you can easily compare across borders and it's extremely loaded with all sorts of issues in the US, as far as I understand.