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

		Budget Backpackers Hostels (BBH) BBH Overview... Kirsty's Opinion - BBH is the card to get, no doubt about it.
		VIP Hostels VIP Overview... Kirsty's Opinion - VIP membership is growing in New Zealand but the network is still nowhere near as large as BBH. Membership comes with a $20 phone card but according to a friend of mine, you have to put extra money onto it before you can access that $20.
		Youth Hostel Association (YHA) YHA Overview... Kirsty's Opinion - YHA (Youth Hostel Association) hostels are renowned for having very clean, safe, boring hostels. If you're heading to New Zealand with the intention of partying then I'd avoid YHA Hostels and not bother buying their $$$? membership card. But if you're travelling with a family or large group, then will tend to cater to you and can always be counted on for quality, even if at the expense of charm.
		Nomads Hostels Nomads overview... Kirsty's Opinion - Chances are very good that you won't come across any Nomads hostels in New Zealand. They have virtually no presence beyond their Auckland Fat Camel Hostel.