These are bush Aussie sayings. I'd say they come from the english heritage of cockney sayings when Australia was settled by english convicts.
Koala in the creek - Celebrate Australia Day 26th January. Cute kids party food idea - Blue Jelly and a Chocolate Caramello Koala with mini Aussie Food Pick
G'day mate, take a gander at this and have a bonzer day
A perfect Aussie spread
Iced Vo-Vo Cake - perfect for Australia Day! - Oh my lord, am sooo making this for Australia Day!
Keep calm and light the barbie
Australia Day Celebrations
Australia Day Poem (apologies to Dorothea McKellar).
Australia Day with Vegemite
Australia Day Themed Party