Road Raven or other middle earthers....

[RoadRaven]

The Queen Charlotte Track is a good suggestion if you mountain bike. My mtb-loving training partner went there last summer for a week with her sister. It was tougher than she thought it would be, but she absolutely loved it. And of course, the scenery there in and around the Malborough Sounds is stunning.
http://www.queencharlottetrack.co.nz/

The cost of getting between the North and South Islands is ridiculous... it is cheaper to fly to Australia from where I live, than to fly to the South Island of my own country. You can get a ferry between the two islands (about 4 hours I think). Taking a car really bumps up the price, but if you walked on/off the cost would be much less. So if you were doing both islands you could hire cars and pick them up/drop them off in Wellington (bottom of North Island) or Nelson (top of South Island).

Queenstown is supposed to be the "adventure capital" of New Zealand, but as such it is also very expensive - both in accomodation and in activities (though my family and I did stay in a back-packers last October and it was reasonable, though dingy). Over the two weeks we travelled in the South Island, Queenstown was not a highlight.
http://www.queenstown-nz.co.nz/infor...rmation-centre

What did we like about the South Island? Orana Park Zoo in Christchurch. We could have spent two days there with the kids. The beaches just north of Dunedin... some of the best kept secrets of this country. Dunedin Museum... would have liked a week to wander round that place. The high country as we crossed from Dunedin over to the west coast... and they have turned the old railway line there into miles and miles of walking or mountain biking track - my partner and I would like to go back and do that. The west coast was a highlight, we only had time to drive up, stopping to look at Fox and Franz Josef glaciers... though you can go for various adventures in and around them... and to look at seal colonies. The scenery was ruggedly stunning and I would like to live there for a few months.

Cheap or free adventure is all over the place here, you don't have to go to big tourist areas. There are loads of bush-walks everywhere (wherever you are in New Zealand you are only a coupl of hours drive from either the mountains or the sea).

Loads of sea fishing charters, trout fishing available in lakes or rivers all round the country.

Taupo (central North Island) offers jet-boating, skiing (water and snow), that hang-gliding thing you do behind a boat, bungy-jumping, white water rafting, etc etc... And an hour from Taupo is Rotorua... geysers, mud pools yes... but also an amazing redwood forest with an wide natural (not concrete) path through it for cycling on. And an hour and a half from Taupo is Hamilton with its river adventures, and glow worm caves.
http://www.jasons.com/new-zealand/ta...ntres-i-sites/

If you came to Hawkes Bay (the "fruit bowl of New Zealand") you would have an art deco city to wander in (Napier), hang-gliding off an easily accessible cliff face (Te Mata Peak), wine tastings (loads of vineyards here), white-water rafting, kayaking (sea and river) para-gliding, mountain biking tracks, road racing (come along as a guest, I'll ride with you)...
http://www.hawkesbaynz.com/travel_in...ation_centres/

If you like diving, there are great diving spots - particularly in Northland, as well as all sorts of water adventures, plus land stuff like bush walks, caving, mountain biking, glow worms, ancient forest.
http://www.northlandnz.com/visitor_i...on_centres.htm

Aero clubs all over the place offer sky-diving and parachuting...

Here's the official Touism NZ website... adventures, travel, accomodation etc
http://www.tourism.net.nz/

Here's also an adventure/eco tourism site that may have some other bits and pieces... whale watching, bungy jumping, bird watching, whitewater rafting, sea kayaking, ...
http://www.nznature.co.nz/ecotourism.htm

So... hope this isn't tooooo much info... and yes, the two main islands of this stunning little country are called, unimaginatively, the North Island and the South Island.