Heading overseas? The last thing you want to do is get home to a $10,000 phone bill due to data roaming costs from internet usage on your smartphone.
Australian Business Traveller recently investigated which mobile networks charged the most for 'data roaming' and found Optus was by far the worst offender, charging a staggering $20 per megabyte -- or $20,000 per gigabyte.
The OECD has also confirmed that Australia is among the worst countries when it comes to data roaming costs.
You can save money on global roaming phone calls with a nifty Skype trick that we've documented here.
If you're travelling with an iPhone or iPad, there's a fantastic app that can slash your data roaming costs by 85%.
But the best advice we can give you is not to use global roaming at all -- instead, use one of the SIM cards from specialist providers that offer rates that are 99% cheaper than the extortionate prices charged by Australian telcos.
If you are travelling to the USA, there's a great SIM card from a company called SIMple Mobile which provides unlimited voice calls, text messages and internet usage for US$80 per month.
There's also a terrific SIM card from a mobile network called Tru that works in both the UK and USA and offers cheap rates for both data and voice calls. It's sold on Qantas in-flight shopping on flights to the UK and USA, which is a handy way to get it.
If you're travelling to New Zealand, we recently investigated the best prepaid SIM cards there. They are readily available and easy to get, so it's crazy to pay global roaming rates in NZ.
For Hong Kong, there's a great prepaid SIM from Three that makes both phone calls and internet access cheap.
In Europe, there's no better deal for internet access throughout your trip than Droam - a 3G/WiFi modem that you rent, that provides 1GB internet usage in many European countries for a month, for just $88.
However, Droam is for data only. If you need a SIM card that does cheap calls and internet access across Europe for your phone, MaxRoam is a great option.
Finally, there's an amazing service called Abroadband that provides very cheap 3G data roaming in 55 countries. The only catch is they only deliver the SIM cards to European addresses at the moment, so your trip will need to start in Europe for it to be useful.