Not a kiwi, but offering a thought on finding other New Zealanders at EYB: there are probably several cookbooks that are owned primarily by NZers, so it might be worthwhile to look over the list of members who have them on their shelves. When you're on the main page for a cookbook, or looking at a title in a list on your own Bookshelf, click the little 'people' icon to see the list of members who have it.
Another clue, though sparser and more indirect, can come from checking the member Notes on the home page often: southern hemisphere cooks are making spring-y dishes when USians, Canadians, and Brits are moving into fall and winter fare. The difference is most starkly evident at high summer/dead of winter. Of course, that'll turn up Aussies, too, and I have no tips for sorting them out... <g>