best way to capture country/city on registration

[DaveHe]

hi all-

We want to capture the country and city of each user as they register, and we want to try and keep it as clean as possible because this data will be super useful for us in the future. Is there a best or standard way to create a dropdown that has all countries in it? I think it's not practical to do that for cities, but maybe there is some best practice for that too??

Any thoughts much appreciated!

thanks!!