Hostel Memberships
There are several hostel networks in Australia which provide discounts to card holding members. YHA, VIP, and Nomads are the big three.

		VIP Hostels VIP is another international membership program, but hostels tend to be more lively and less regimented than their YHA counterparts. A VIP membership costs $41 for one year and $55 for two years and with it you get a useful book with a list of all VIP hostels worldwide. There are LOADS of VIP hostels in Australia. Membership usually means $1 off a night, but this card also gives discounts all around the country on tours, entrance fees, and transportation among other things. Kirsty's Opinion - VIP hostels have a list of rules to adhere to, just like YHA hostels, but they tend to vary more in their overall quality. While you can almost predict what a stay at a YHA hostel will be like, VIP might impress you in one city and let you down in the next. Unlike YHA though, there are often several VIP-affiliated hostels to choose from in any given city, so doing a bit of research will help avoid the bad places. I would definately recommend buying this membership. The discounts given on things like tours and transport are plentiful and often large and you'll cover the cost of the card in no time.
		Nomads Hostels Nomads is a smaller network of hostels that seem to be generally found in smallish towns and harvest work areas. This membership costs $29 for a year and gets you $1 off per night or the 6th night free if you stay in any one Nomads for a week. Your Nomads membership card is also a calling card that can be recharged. The card also gets you discounts on the usual tours etc, but not in the same capacity as VIP. Kirsty's Opinion - You could survive fine in Australia without joining this network as you might never even see a Nomads hostel anywhere on your travels. But if you want to get off the beaten path or work in odd places then it might be worth it. I'd suggest not buying it in advance and instead getting it at the first Nomad's you come across that you want to (or have to due to no other options) stay at.
		Youth Hostel Association (YHA) YHA hostels are the same as HI (Hostelling International) hostels found in other countries, and their discount card is valid. A new membership costs $52 for a year and a renewal costs $37. If you commit to a two or three year membership you'll save. Membership provides you with discounts (generally $1/per night off at Australian hostels) at over 4,000 hostels in 60 countries, as well as discounts on a variety of tourist sites and even at stores. The YHA/HI card will generally give $1 per night off accommodation. Kirsty's Opinion - I've never been a fan of HI/YHA hostels that I've been to in Europe and around Australia. They're always really clean and secure, but I find them very sterile and boring. There are, no doubt, exceptions, but as a whole I prefer to stay in independant hostels with more character. But if cleanliness and security are your main concerns then I'd recommend buying a YHA membership because you'll be happy with the hostels. If you'd rather meet people and have fun then save your money.