I am overwhelmed, truly. I realise that 52 comments is a slow day on the internet for some people, but it was awfully exciting for me. Thank you to everybody who took the time to comment. I began answering but can't possibly keep up, so please just know that I loved reading every single contribution, and have answered some things below.
And now for your enjoyment, here are some more that I thought of the instant I hit 'publish' last time.
op shop: thrift shop, charity shop
ring: call (someone on the phone)
bathers: togs/swimmers/cossie [abbrev. swimming costume]/swimsuit. This one varies regionally. We say bathers, my NZ aunt says togs, Bec & Kim may wish to pitch in here with the Sydney version
boot: trunk (of the car)
soft drink: soda/pop
hot chips: chips, french fries
rubber: eraser (the bane of my year as a schoolgirl in the US. "Can I borrow your rubber?")
takeaway: takeout (food)
arse: ass (similarly, arsehole) Ok back to family friendly blogging ...
fullstop: period (a period is something else entirely)
icy pole: iced lolly/popsicle
muslin: cheesecloth (?)
trainers runners sneakers plimsolls all regional variations but my personal favourite is brothel creepers
trash can: rubbish bin. When I lived in ID (see, I can do it too if I concentrate) my two host brothers thought this was hilarious. Their college friends would come over and they'd say "Hey Suse, come and tell Brad/Todd/Chuck where you would put this piece of garbage!" and I would perform and they would laugh and pat me fondly on the head from their great height (everyone in ID is 6'4").
Put it in the too-hard basket: to give up (A commenter pointed that out. I didn't realise it wasn't universal. My basket runneth over currently.)
Flat out like a lizard drinking: to be very very busy indeed
Drive the porcelain bus: to vomit (into the toilet)
Technicolour yawn: vomit
No worries/Not a problem: it's fine
Spit the dummy: throw a major tantrum
Chuck a wobbly: again with the tantrums
It's all gone pear shaped: when things go awry. This one is English but it's well used here.
Melt my wax: surfing term, as in a surfer would spot a hot chick [as opposed to hot chips] and say she really melts my wax. Could be out of date by now, I have not been a surfie groupie for some years.
I've also noticed differences in some past tenses. We say knitted and fitted and spat. As in "He rang me up to say that the new jumper I knitted him fitted perfectly but then the cat spewed all over it so he spat the dummy and put the whole thing in the rubbish bin."
There are indeed class-based accents in Straya. Just try saying "noice, roolly roolly noice" in your best Kath & Kim accent on a tram full of eastern suburbs private schoolgirls in their straw boaters and feel the atmosphere freeze.
Regional differences are also developing. People from Adelaide and Perth sound somewhat different to eastern state folk, sort of New Zealandish but not quite as ludicrous. (Kiwis really do say fush and chups, honest). And everyone says we Victorians have an accent. (We don't of course). I can't even begin to describe the accent of a Queenslander. More Strine than Strayan I would say.
Personally I grew up with two very English parents and then married an Englishman so many of my words/pronunciations are English. My friends all think it's hilarious that I sit on a settee instead of a couch or sofa, and I only recently stopped hoovering and took up vacuuming. And I put bandaids on my children's scabby knees rather than plasters these days.
Now, to answer some commenters questions, a jumper is a sweater. What you call a jumper (a sleeveless dress?) we would call ... um, a sleeveless dress. Or a shift dress? Perhaps a pinafore?
A vest in England is a sleeveless undergarment, known as a singlet here. Long sleeve ones are called spencers.
I'm sorry I have no idea what a duchess is, except what you become if you marry a duke I suppose.
We just don't do dried meat so there is no jerky/biltong equivalent. We have refained tastes here y'know.
And a rusk is a baby's teething biscuit, an adult would never have one with her tea unless she was terribly premenstrual and the pantry was bare.
We do say reckon a lot, but I reckon everybody does, eh?
And of course, it is the ENGLISH who say flip flops. The Kiwis say jandals. My apologies.