UPDATE – It turns out that the USA Visa Requirements say one thing but the border officials do another. Because New Zealand is a Visa Waiver country you just need to apply for the regular ESTA to go in and out of the USA from Canada. As long as you have a valid Canadian Work Permit and the ESTA then you should have no problems at the border.
I struggled to figure out what visa I needed to visit the USA because I will not be leaving North America afterwards. As a New Zealander I qualify for the USA visa waiver program, however, in order to be allowed to travel in the USA using the visa waiver, you pay about $10 a couple of days before you travel and need to have a ticket out of North America within 90 days and it cannot be to Canada, Mexico or the Caribbean Islands. This poses a problem since I will be heading to Canada for 2 years using the Canadian Working Holiday Visa. With this problem on my mind I called the American Embassy in Auckland to ask what to do and was told that they could not advise on choosing a visa. Great. So I asked google and could not find a lot of information on this issue. In the end I worked out that I needed a B2 Tourist Visa. This visa is valid for re-entry and lasts for 10 years. Pretty ideal since I will want to visit the USA again while living in Canada and you only have to prove you don’t intend to stay in the USA and don’t require an air ticket out of North America. It costs a visit to the US Embassy for an interview (book at least a month before you travel) and a whopping USD$150! Something to add to the budget.