translation internationalisation

Say we have some sites: uk.example.com, us.example.com and fr.example.com. the last one uses our French pages, the first two use our "English" pages. Is there an easy way to handle the minor but noticeable differences between American English and British English. It seems a pain to create separate nodes for all pages (or even one page) just because of the words "colo(u)r" and "meters"/"metres".