If you live in coastal south-eastern Australia, chances are you've encountered at least one frog species. And this is probably it. It's the Common Eastern Froglet, Crinia signifera. You've probably at least heard its call - vocalised even in the day, all year round. Curiously, individual or groups of males call in concert and out of phase with other individuals/groups. Hard to explain, but basically the classic 'call' that you hear of this frog is made up of at least two frogs at different pitches.
I found the frog on the left (photographed semi-submerged in water) when out in the bush a couple of weeks ago - it appeared swimming around in a small pool in a stream. Despite my presence, it kept its vocal sac semi-inflated.
It reminded me of a C. signifera that I found a few years ago (pictured right). This frog stayed completely inflated despite being handled, prodded and photographed!