Looks good. Just like ziptastic and all the others, but with international support. That's a real advantage.

I've always wanted to use such a library for my checkout forms and whatnot, but unfortunately it doesn't fit the typical UI paradigm.

If you need the address info, you'll (almost) never ask for the zip code before the city and state, so the information has already been filled in before the user gets that far... and the country comes last.

Users are used to entering the address info in that natural order: street, city, state, zip, country (usually pre-set to your biggest userbase). I think the cognitive overhead of mixing that order up actually exceeds the effort of having them fill in all 3 fields.

The only place I could see you using something like this is if your are tailoring your services to a US-only userbase (so you can guarantee that a zip code is there and that the other info will not need to be manually entered). For example, we use ziptastic (at the server side for cross-domain reasons) at http://gastomorrow.com/ which is a US-only service to guess the price of gas tomorrow in your area.