Here are a few things I miss from Australia...
Twisties,
The ultimate cheesy snack, better than any potatoe chips.
http://en.wikipedia.org/wiki/Twisties
Tim Tams
The tasty choclate biscuts ever, they have somthing similar here in the U.K called Penguins. But they just don't compare.
http://en.wikipedia.org/wiki/Tim_tams
Big M
Sure, you can get flavoured milk anywhere, but this is the tastiest flavoured milk around. available in 300ml or 600 ml cartons, it goes great with a pie or pack of twisties... Iced Coffe is my favorite flavour.
http://en.wikipedia.org/wiki/Big_M
Murray Cod
One of my faveorite fish, hmm, when I was a kid one of my brothers would catch some huge ones up to 80 kg, we always had plenty in the freezer. It is best on the B.B.Q.
http://en.wikipedia.org/wiki/Murray_cod