it was the comedian Paul Hogan who said "shrimps", as I recall. There are 20 million other Australians and chances are they say 20 million things. If there aren't enough coals on the barbie, then "coals" it will be.
Only problem is ... we don't call them shrimps down here, we call them prawns - never quite worked out the reasoning behind paul saying that - maybe it's aimed at tourists - anyway the saying is 'put another shrimp on the barbie'