How many of those have you run across Shannow?
Tiger snake - twice, once in the bush, once crossing a rail bridge here in town.
Copperhead - twice, including one crossing the road while I was driving (found in the power station twice)
Sea Snake, three times (caught while fishing when I was a kid in Adelaide).
Red Bellied Black - probably 6 times usually out in field, near creeks, open cut areas...one I nearly stood on, and it was huge...
Eastern Brown - three times - they are agressive, and will fight you one launched at me as I rode through a pine forrest and hit the bike behind the pedals.
Coastal Taipan - I reckon once or twice...there was an unusual brown snake in the Yass area when I worked in transmission. An ameteur herpetologist in the area counted scales, and reckoned it was a taipan...sure enough years later, it was identified in that region.
Things that go shooting through the grass, bush and blackberries and cause heart to stop...many many times, including my yard.
Having one of our many species of large lizards poke their head out of the garden, under a log or whatever...they give you the same feel until they flick their tongue.