Flying into Australia via Sydney? Look if your not already, adjust your flights to give you at least a 6 hour layover in the middle of the day. Once on the ground check your baggage to the next destination and then if needed, check your larger carry ons except a small bag for your important stuff at the baggage storage place nearest your gate. Then head on over to the greenline train station and purchase a round trip ticket to the Circular Quay (<$40 Aust). Sit back and enjoy