Hi kismet,
I have moved this topic to the "real aviation forum" as it is not really to do with flightsim.
I too use a scanner bought from Dick Smith Electronics, made by Uniden:
http://www.dse.co.nz/cgi-bin/dse.storef ... View/D2764 It costs $300 but is well worth it, as it has a very large frequency range, from 25-512MHz so it can pick up just about everything, including armature radio, police, fire, ambulance, trains, marine and of coarse airplanes!
With the standard Arial, you can hear airplane transmitions fine, but I plug mine into my TV antenna with a little connecter that cost $2, and receive much clearer transmitions for further away (Whangarai, Great Barrier, Mercer) from my house in East Auckland.
Going down to the seafront, or up the top of a volcano (there are heaps round Auckland) also is a good place to get transmitions, but my favourite place is the carpark on Puhinui Drive near Auckland Airport, as you can hear all the inbound planes, as well as the tower, and the ground handoffs telling them wear to park.
It was Jarred (NZ1 on the forums) who actually got me into all this, so if you have any further questions, ask him. We both have the same model scanner
Check out this thread:
http://s11.invisionfree.com/nzff/index.php?showtopic=20 for more info.
Cheers.