We loved Queenstown, but we did so much adveture sports and then we were a bit bored after our 5 days there. I suggest you sky dive there - amazing. Much better than lake talpo or rotura. You should not miss Huka Falls or Marborough or wellington!! The marborough sounds and wine country are stunning. So much beautiful country to see. Can't jason get a Treo;). Rick loved Christchurch, but it was too cutesy for me.

There is also Sheep World (http://www.sheepworld.co.nz/farm.htm)
and Zorbing (http://www.zorb.co.nz/). Both next to each other.

There is also the tower to jump off in Auckland:
http://www.skyjump.co.nz/

Bungy jumping at it's first commercial site:
http://www.ajhackett.com/index.php/pi_pageid/17

Zorbing is great.
If you can find it Cow World is also pretty cool.

If you make it to Queenstown you should take a day trip to Milford Sounds. It think it was the most beautiful place I have ever been. In between is the Te Anau Glowworm cave.
http://www.realjourneys.co.nz/index.cfm

If you go bungy jumping , AJ Hackett may operate the original but it also operates the 2nd tallest in the world. http://www.ajhackett.co.nz/index.php/pi_pageid/29 .

The Speed boats are pretty awesome too. http://www.shotoverjet.com/

Kaikoura has some amazing marine life. Go on a whale watching trip and you are also guaranteed to see some dusky dolphins. They are the most acrobatic species of dolphin. You can also go swimming or diving with the seals.
Check out the Shark diving. They put you in a cage off the back of the boat with 12 foot blue sharks circling the boat.
http://www.firstlighttravel.com/dive_loc_kaikoura.html
http://www.naturallykaikoura.co.nz/