
It can get extremely expensive calling home from Rome, or really from anywhere overseas.
The best thing to do when you first arrive, is to buy a phone card from the many Tabacchi (like a mini newsagency) around the city. Ask for a Scheda (pronounced skeh-dah) and they will know exactly what you are after, providing you explain which country you need to call. It works like any phone card we buy in Australia and depending on what type Ie. Telecom Italia for example, you can sometimes talk for an hour for only 50c to $1.00. Some further details on types can be found at http://www.initaly.com/travel/info/phone.htm
Some older bars still have phones that take tokens - Gettoni (pronounced Jeh-toh-knee). Whatever you do, DO NOT use one of these! You can end up paying $1.00 per second with these machines and Romans / Italians are no different to Australian's in thinking that there is no excuse for ignorance. Although I am speaking from experience, in my defence, when I last used one of those wretched machines, mobile phones never existed and nor did phone cards. So if a barman suggests you use his 'special telephone' ... don't.
For 'just in case' situations or for emergencies, I would strongly recommend getting Global Roaming. In this day and age, every one of us holds a mobile phone, so we all have access to it. It does equate to paying a little more than usual for the calls you make and unfortunately, you also pay for the calls you get (as does the caller). But for peace of mind, it is always good to have 'Plan B' up your sleeve.
The below web site also gives you most of the area codes for countries that you may decide to call to once you are in Rome. It is extremely handy, so I would suggest writing the area codes for your preferred dialling destination into a handy book of tips ... http://www.enjoyrome.com/tourist/cityguide/mail.and.phones.html