We are coming from the US. Will I need an electric adapter for our camera chargers etc.??

coming to where??

If Oz - definitely yes - our electricity is 240v

Take a look at your charger. Most new chargers work on 110 - 240 volts. So all you would need is a plug adapter.

And our plugs have 3 pins and sockets have three holes, not two.

Mover and I must have answered that at exactly the same time - the difference in no of pins and holes is easily overcome with an adapter, of course.

Here is a good website about international electricity. It has photos of adapters (that enable you to plug an appliance into a wall outlet or socket whose holes are configured differently from the pins of your appliance's plug) and converters and transformers (that "step down" a 220 volt electricity supply for a 110V appliance or that "step up" a 110V electricity supply for a 220V appliance).

http://www.walkabouttravelgear.com/elect.htm

If you're going to New Zealand, you'll need an adapter.

Lee Ann