The plug on the device themselves may be different, but on the USB side of the plug (the side that connects to the PC or charger), MOST devices should be universal. Since the Kensington is a universal charger and not device specific, it should work fine within the listed voltages (100-240V), although you will need a country/region specific adapter to make use of the different plug style with this charger.
New Zealand uses 10A, 240V, 50Hz outlets which is all within range of the charger itself, so all you will need is the plug adapter.
Amazon has a cheap adapter:
http://www.amazon.com/ATLONA-UNIVERS.../dp/B000VMA0KW
Also, make sure you only use devices rated at 100-240V and 50-60Hz with this adapter. If it is 110 only, or 60Hz only (or both) you will likely fry whatever item is plugged in to the adapter.