Cyberclinic: Which of the many ways of calling abroad is cheapest?

"Low-cost international calls at fantastic rates!" It's a familiar advertising message. Indeed, on some high streets, it's impossible to get from one end to the other without accumulating a handful of flyers for budget phonecards. As a nation, we have probably got the message that we are better off not dialling directly from a landline or mobile when calling abroad, but the number of options can seem bewildering – while the market is enormous, it's also extremely fragmented.

Budget telephony companies resell to us the "minutes" that they've bought from the owners of the infrastructure, but with so many of them seeking a foothold, they tend to specialise in particular destinations – bulk-buying minutes, undercutting rivals and securing the loyalty of a particular ex-pat community. However, they're all keen to get a slice of the UK to USA phone action, and this has driven prices down to rock bottom. "These days," points out one reader, Stefan Weiss, "no one should be paying BT or OneTel an exorbitant 75p for a five minute call to the States. Any phone provider worth their salt should only be charging between 5p and 15p."

Few of us have a truly multinational phonebook; we're more likely to have a handful of non-UK numbers that we call fairly regularly. By using the handy tool at callchecker.moneysavingexpert.com you can check up on the best deals to particular destinations. Many of these services require no sign-up procedure – just dial an access number and you're away. "I call my family in Hungary using an 0844 service called Telesavers," writes Ildi S, "and it only costs me 1p per minute."

Once you're familiar with the ballpark rates, it's worth checking out calling cards, too; these are pay-as-you-go services, but they're similarly competitive. Also, if you have broadband, a computer and a headset, check rates with services such as Skype and Vonage – and remember, try to persuade your friends and family to also invest in a headset and sit at their computer while you exchange gossip, it will all be free of charge.

Distance should, at least in theory, be an irrelevance in today's telephony market, a point stressed by Mat Goff at Rebtel. Their service offers the cute, inexpensive trick of assigning your friends abroad with a local British telephone number, which you store in your mobile phone – the service drastically reduces your bills. "If you call the USA a lot, and you want to do it from your mobile for 1p a minute," says Matt, " Rebtel is... well, almost stupidly useful." These days, if claims sound too good to be true, it is worth investigating, regardless; innovations such as Rebtel's will continue to spring up, and continue to change the way we make phone calls.

Diagnosis required

Next week's question comes from Clive Burroughs: "I was interested in setting up my own internet radio channel – but I've heard that the whole idea of internet radio is under threat. What's the score?"

Any comments, and new questions for the Cyberclinic, should be emailed to cyberclinic@independent.co.uk