Since moving to Dicky Beach about 5 years ago I've seen a lot of the suburb and the beaches and dunes and noticed all of hte wild fruiting plants around the place.
Here's a list of what I've found within an hurs walk of home - what do you have growing nearby - and just ready for the taking?
monsteria deliciosa - the plants and the fruit
guava - several types, cherry, yellow, and a yellow as big as a baseball
lilli pilli - dozens of types - nearly all edible, some very nice
loquat
bananas (I think they are ladyfinger - the possums use them as a food source - our possums are nothing like the ones you have in the USA)
prickly pear
pigs face (Disphyma australe and
Google Image Result for http://www.hartill.net/Oz/Images/IMG_1670.jpg can't find the botanical name for it)
oranges, lemons, rough lemon, olives, midyim berry,
blue quandong (supposed to be edible, I think the books have just used edible to describe something that isn't poisonous - a foul tasting fruit)
and more that don't come to mind just yet