Q:

New Zealand visa longer stay?

In the USA if enter with an ESTA you can stay 90 days but if you have a B1/B2 visa, you can stay 180 days (and have the possibility of extending even that with a I-539 form). 
I am a citizen of an EU country and as such I am able to enter New Zealand without a visa. However, I am unable to find how could I stay longer than 90 days -- based on the USA example I was thinking maybe if I got a visa? 

A:

There are ways to stay longer than 90 days in New Zealand, even as a visitor. For example:

If you are under 30 (and meet some other conditions) then you may be eligible for a Working Holiday Scheme visa which lets you stay for a year
If you apply for a Visitor Visa you may request a duration of stay longer than 90 days

If you intend to work in New Zealand, such as if you have a job offer, you can apply for various temporary work visas. You may even apply for such a visa after you have arrived in the country as a tourist.
The Immigration New Zealand web site is well laid out and presents the various visa options clearly (see "Find a visa").

