We came back from corfu two weeks ago. I have a pay as go phone on 02, but it WOULD NOT WORK AT ALL. despite checking with 02 and getting their abroad 35pmin approval. Other peoples in the apartments worked!. got really annoyed, had to find a phone every night to phone home (my daughter is pregnant and had to check she was okay). When we found out the phone would not work we spent most of the evening trawling around and tried 5 payphones before finding one that worked and one even gave my husband a shock in his ear when he tried it. !!!
So dont rely on payphones, although they are cheaper than mobiles you cant always find one. and of course then no one can contact you in an emergency.
My advice is take a mobile, make sure it works, (for emergencies), dont ring home, forget everybody at home, after all YOU ARE SUPPOSED TO BE ON HOLIDAY !!