If you are single, are under the age of 30 and have a British passport - you will qualify for a 2 year working holiday visa. This is a great way to live and work in New Zealand while at the same time being able to discover what the country has to offer.
There are a number of other "working holiday" schemes. South Africa does not currently have one however.
Follow this link to see the counries that have similar schemes:
http://www.immigration.govt.nz/migrant/stream/work/workingholiday/