most places in europe you can get cheap pay as you go mobile phones. shops and supermarkets sell them. you can get a cheap local sim only deals too. lots of mobile phone shops an supermarkets sell them.

if your own phone is unlocked and has the right bands for EU, you can just pop the sim in your own phone.

if you have a laptop and internet access / wifi/ hotel etc have you considred skype for the long distance calls? i find it very handy for calling home etc, where they are all on skype and we can chat away for free