It still costs you though if you are in Europe, if I understand correctly, so both the person making the call gets charged and the person receiving the call gets charged !
Keith, do some shopping around - the EU is clamping down on European roaming charges big time (pushing for zero premium for international calls) and all of the operators have already cut their charges by up to 50%.
The Vodafone Passport option might be up your street as there is a setup charge per call but after that you get charged your UK rate. It's no good if you make lots of really short calls but the numbers might work for you if your calls are slightly longer.
You should also look into Vodafone's "Stop the Clock" option as well if your calls tend to go longer than 3 minutes.
I'm with o2 and have to do a lot of travelling around Europe with my job. They have a set scale for all European countries so suggest you contact them on 0870 586 0860. Tell 'em Mikey sent you!
I was with orange for years, changed to vodafu**wit network and got stitched up when abroad for calls, so went back to orange far cheaper, so far have yet to get insane bills, but that could always change tomorrow.