I’m moving a landline to VOIP and my service provider has a handy table comparing VOIP international calling rates from different vendors.

I averaged those rates by country:

The cheapest countries to call are Israel, Canada, the US, France, Germany, Spain and Australia.  Geography shouldn’t matter in this analysis, because it’s all done over the Internet.  With the exception of Israel, the Middle East is expensive, presumably because of a lack of competitive markets.  Oman, the United Arab Emirates, and Saudi Arabia are the most expensive countries to call.   Mobile phone are more expensive than land lines, presumably because of higher costs associated with mobile infrastructure.  But, surprisingly, both Spain and the UK have very expensive mobile phone rates: the UK’s is the fourth highest of all, and second among all mobile phones.  Why is that?

It would be interesting to look at the geographical range of rates and to compare mobile vs. fixed line rates.