One of the things for which I've never been able to obtain an even half-way satisfactory explanation is why the Australian and New Zealand accents are so similar and yet are so dissimilar - and why they are like no accent anywhere else.
I can be in a very crowded Oxford Street (or any other similar location), and all the varied accents around me will simply wash over me, yet a Zild or Strine accent will perk up my internal radar at the drop of a blip.
I've seen all sorts of hogwash along the lines of "lower class English convicts were transported to Australia and the accent is a corruption of theirs". But sorry, it doesn't wash. New Zealand never had transported convicts and it wasn't largely settled from Australia.
I should point out that I studied computational linguistics as part of a post-graduate diploma rather than the "softer" areas, although I wish I had had time to do both. I attended anything that looked interesting, though. Therefore, my understanding of the area is pretty limited. SWMBO would say that my understanding of any area is limited ...
All opinions (on the origins of the Australasian accent) eagerly sought!
How posts does this make it, Xara? You appear to be taking over MQ's mantle in this area.