Down Under, Day 6: Australian For "What?"

You know the cliché blog post about Australian lingo was coming sooner or later, and here it is.

A Brief Selection from the Idiot's Guide to Speaking Australian
(NOTE: This is not brought to you by Foster's Beer)

Banana bender : a person from Queensland
Big Smoke: a big city, especially Sydney or Melbourne
He doesn't know Christmas from Bourke Street: he's a bit slow in the head. (Bourke Street is a brightly lit Melbourne street)
Brown-eyed mullet : a turd in the sea
Built like a brick shit house: a very strong bloke
Coldie : a beer (take a note, Foster's)
Fair dinkum : true, genuine
Figjam: Abbreviation for "F&*k I'm good, just ask me" - one who has a high opinion of themselves
G'Day : Hello
GAFA (pron. gaffa) : the big nothingness of the Australian Outback. Great Australian F**k All.
Kangaroos loose in the top paddock : Intellectually inadequate ("he's got kangaroos loose in the top paddock")
London to a brick : absolute certainty ("it's London to a brick that taxes won't go down")
Maccas (pron. "mackers") : McDonald's
Swagman : tramp, hobo
It's gone walkabout: it's lost, can't be found

Based on the small sample size, I'd say Aussie's favorite thing is to create creative local slang for calling somebody slow-witted. Not that there's anything wrong with that; we have many such local-isms back home ("The engine's running but nobody's behind the wheel", "you're not playing with a full deck of cards", "the lights are on but nobody's home"), but they have a curious flavor to the insult that is unmistakably Australian. Nobody else could work kangaroos into a scoff about somebody's brain power.

As a closing note, have I ever heard any of these sayings apart from the occasional "G'day?" The answer, as you might suspect, is no (apparently there's no colorful way to say "no" in Australia).