If you are using mobile data services in New Zealand, don't roam on your overseas SIM card. You could easily pay $NZ 30,000 per Gbyte. Buy a SIM card or USB stick from Vodafone, 2 Degrees or Telecom. 2 degrees has the cheapest pre-pay calls and now also offer 3G data services and USB broadband sticks.

May 2011: currently there is a battle happening on overseas roaming rates for NZ telcos, 2 Degrees have announced $2.50 per MB in Australia, Vodafone have countered with $0.50 per MB. Now $0.50 a MB is $500 a GByte, 500 times what we pay for data on a landline. None of them are trying very hard.

Here is how to make your USB broadband stick work in NZ or overseas. This method shows you how to stop the automatic startup to the default carrier, and how to use MWConn freeware to use any SIM worldwide and get the cheapest data rates.

I no longer sell callback phone services, as a range of cheap phonecards are available from most shops and dairies in NZ. I suggest you avoid the cards with high rates from NZ Telecom, NZ Post. Here are some examples:

• WorldNet prepaid phone cards
• EasyCall

Vodafone operates a GSM service at 900 MHZ in NZ. They have a Prepay Connection Pack for visitors to New Zealand. The pack contains a local Vodafone Simcard and $15 of prepay airtime, and costs $35. To purchase a Prepay Connection Pack call in to any Vodafone branch nationwide or order online at Vodaphone.

A new GSM operator, 2Degrees has brought some long needed competition to the NZ market, they started operations in August 2009 with calling and texting rates about 50% of the rivals. Their phones and SIM cards are in supermarkets and local dairies. They have 3G service in cities, outside the main cities they use the Vodafone 2G network.

Telecom operate a CDMA cellphone service that is incompatible with GSM and will be turned off in 2012. They have recently introduced a GSM-based WCDMA 3G service known as XT that was launched in May 2009. Type 'compatible phones' into their search box to see if your GSM phone is compatible.

You can rent GSM mobiles from the Vodaphone shops at the major airports, but you will probably be better off buying a SIM or SIM + phone package from 2 degrees and get it delivered to your hotel. Most supermarkets also sell them. Here is another phone rental company Cellphone Rentals NZ.