Heron Island off the coast of Queensland must be my favourite place. I've bin there twice. Once in the 70's and again in 1998. The first time I was lucky enough to see hatchling turtles heading down the beach to the sea. The next time giant turtles were being checked and tagged by a team from the Uni.
There are no permanent residents other than the staff of the pretty uncommercial accomaodation setup.
You can walk around the island in about half an hour - but why rush.