Hi!
Wikipedia contains many categories of subject by country. There ~ 200 countries, so in many cases interwikis for such categories could be missed.
I think will be good idea to create bot which will generate interwikis by using 2 sets of parameters:
1) Template for generating dictionary of country names - category names on 2 languages (for example English and Russian) which already well interwiked: "National symbols of %s", "Государственные символы %s".
2) Templates to generate new interwikis: for example "Football in %s", "Футбол в %s"
I think such bot will definitely help to avoid routine work.
Eugene.