I happen to live reasonably near to the airport in my home town (Christchurch) and as such it seems to fall upon my wife and I to act as a taxi service to and from the airport (not to mention the car storage!) for relatives and friends. As such I am often looking up arrival times and departure times.
I have discovered a thoroughly useful wee app called "Flightboard" by Mobiata which displays arrival/departure information live on my iPad. There is also an iPhone specific version.
This works with the airport in my city and from the time I've spent searching various airports in New Zealand as a whole it covers pretty much them all – including regional airports.
For anyone who, like me, is often looking for this info on the internet then this app is a great addition to your iDevice :)