I couldn't find any existing libraries to help format international
mailing addresses. Turns out it's rather tedious. Not only do
different countries have different names for the components of an
address, but many countries have different formats for the city line.
And then there's Great Britain, er England, er ... yeah.
So I've started work on a plugin called Snail. My dream is that it
will grow to encapsulate the rules of international address formatting
and basic validation. It's just quite a lot for any one person.
The first release is up on GitHub at http://github.com/cainlevy/snail.
If your application has anything to do with addresses, and you think
it may need to go international, I hope you'll check it out!