Well, we can all get caught out and just for fun here are some lessons learnt the hard way!

The root of the problem is that the iPhone, with all its apps, positively radiates data. Domestic plans feature unlimited data and so few users bother to track the amount they send and receive.

If you don't sign up for any international plan and use your phone as you would at home, checking e-mails, sending photos and getting directions can cost hundreds.

It will cost you extra, but there are some steps you can take to limit the damage.

Incoming calls that go to voice mail cost - so meandering messages from friends are unhelpful.

If you like to check on e-mails, view maps or update Facebook you should sign up for an international data plan - the cost can be 1/20 of not making any special arrangements.

If you happen to be staying somewhere with wireless internet access, you can dodge most of these charges. Establish a connection with the network and use Skype or another Internet phone service for all voice calls and use the wireless network to surf the Web and check e-mails.

Leaving the phone at home is not an option, we know. But it isn't going to be nearly as cheap as at home and could give you a nasty post vacation surprise!