If you're interested in learning Sign Language (Auslan), DSQ would probably be one of the best services to go through - and they're rather flexible. I've completed Auslan Level 1 and 2 - and that was moving between Brisbane, Townsville and Cairns. Lessons in each town start at the same time and they cover the all the same content so if you are travelling and don't want to miss a lesson, just message DSQ and they'll advise you of where to go. Discounts are provided for students as well. Good service and a good skill to have.
Approximate cost: $120