suggestions / requests for the flags add-on:
-support unabbreviated country names (i made it set the tag to the country name in text instead of using a flag, so the 99.9% of the people w/o the client add-on can see)
-use a site that doesn't have a 1,000 a day limit for API requests if possible
-if the latter is not possible, implement a feature to trace a users IP to their country once, log it, and check the user's ID for stored data, before requesting a check with the site
by using this last suggestion, you can log up to 1,000 new user's country data each day and avoid hitting the limit in the future, because they will be checked against the log before a new IP trace request is sent.