Backpackers places are so common over here. Go to google and type in "backpacker hostel" in google.com.au. Loads of them. My friends are in one called the Friendly Backpacker I think.
Oz visa - up until recently the legislation was. 1 12 month visa per person per life. That is valid for 12 months from the time you land in oz and you have up to 12 months to take it. i.e you apply in January 2005, have up until January 2006 to land in oz and then 12 months from there so out in January 2007.
Rules used to be 2000pounds and a return plane ticket or at least outbound of oz or 3000pounds in savings and no onward ticket. You have to send off a bank statement to the Australian High Commission in London which is in the Strand I believe but google can confirm.
Oz visa limits you to a total of 9 months work in the 12 months you are in oz but you can only work for one company for not more than 3 months.
New Zealand I dont think you need a visa for holidaying and can stay up to 6 months. Oz you get an ETA (Electronic Travel Authority) for 20 quid from a travel agent for a 3 month holiday.
Oz I know most about as I have been living here on and off for nearly 4 years now and have been through residency and visas etc so anything I can help with there, just ask.