the situation will be a crowd of us camping at the World Microlight Championships in Spain. The organisers have laid on wireless broadband and mains power. No doubt there will be members of the UK team who will want to call folks back home. My Vonage hardware connects over the internet to a landline connection somewhere in the UK and from there it gives me 24/7 free calls to UK landlines. If I take it to Spain it should still work just the same as it does when in my office in Berkshire, free calls to UK landlines.
If I install Skype (or similar) I have to pay for calls to non-skype destinations.
Rans6....