I now have 198,586 cities in my database, complete with latitude and longitude for all of them. As a result, my pet project allows you to click on countries, see the regions for that country and then click on a region to get a paged city list (1576 cities just for New South Wales) and see a map of any city you click on.
The site still doesn't do anything amazing and it's not particularly user-friendly. That's because I'm discovering that managing data quality is really hard when working with only free data. Not quite sure why American Somoa has a region named "00", but there you go. In fact, I have 54 regions in the database named "00". Lots of slogging through here to understand things.
(Who the hell spends time coding on their vacation?)