This article is from the New Zealand FAQ, by Phil Stuart-Jones and Lin Nah with numerous contributions by others.
Visitors to NZ must have a valid passport. The only exceptions are
children under 16 who are included on the passport of an accompanying
adult. Passports must be valid 3 months beyond date of departure. Visas
may be required depending on nationality, purpose of visit, and intended
length of stay. Visas are not required of US citizens in possession of a
return or onward ticket staying up to 90 days.
Australians and NZers need passports to get into each others countries.
NZers now need visas too, although these tend to be no real difficulty.
To find out more about the Visitor's Visa or Permit and how to
apply for it, please refer to:
http://www.immigration.govt.nz/visit/
 
Continue to: