Palms Royale in Cairns is where I'll be staying!
I found a hotel called the Palms Royale which is about 8km/5mi from the airport. It appears to be a nice clean place with decent enough reviews. I got the room on Wotif.com for $50AUD! That's a steal compared to the published rate of near/over $100AUD! Thanks for the recommendation - plus they have a customer service number for the United States which helps.
I had no idea the Cairns airport closes at night! That makes my choice of whether or not to get a room pretty easy.
What time does the airport open back up??? I'm leaving on Air Niugini for Port Moresby the following morning around 07:00am (0700hrs). Since it's an international flight out of Cairns do I need to be there 3 hours prior to check-in or two hours prior???