If you can't afford international phone calls (or your girlfriend's), a callback service is one of the answers (Internet phone is the other). Being in Japan, this is especially true: KDD (the Japanese international phone company) rate per minute is ridiculous.

Even more ridiculous are international calls from hotels. A few years back, I was staying in a hotel in Boston and called France for 20 minutes. The bill was US$180 for that phone call! It would have been around US$5 with a callback, 36 times cheaper.

Here is how a callback works.

1. You sign up with a callback company (you give them your home phone number and your credit card number) and they give you a phone number. It does not matter in which country you live, you can register with any callback company (most of then are based in the US, which hosts the cheapest phone companies in the world). Once you have signed up, you can use their services any time you want, as often as you want.
   
   
2. When you want to make an international phone call, you dial the number that the callback service gave you, wait one ring and hang-up. There is no charge since nobody on the other end picked up the phone. A few seconds later, the callback service calls you back (that's why it is called callback) and when you pick up the phone, what you hear is a dial tone. Now you can enter the number of the person you want to call.
   
   
3. The charge for the call will be the call from the callback computer to your home (using the callback phone company, not yours) PLUS the call from the callback computer to the person you are calling. For instance when I, in Japan, call my sister who is in France, my callback service charges me the US-Japan + US-France connection. Since callback companies have many subscribers, they buy phone lines in volume from phone companies, enjoying a very low rate. And since the administration of the callback service is entirely done by a computer, the overhead of the callback company is minimal. All to your advantage.

Now this is the traditional callback, where the callback service calls you back at the home number you registered. What if you are staying at a hotel or at your friend's place. Many callback companies have what is called Direct Call. Instead of being called back, you dial a toll free number in the country where you are, and from there enter the number of the person you want to call.

So what you want is a callback company that has BOTH callback service and Direct Call service. I was using Access Authority; there were pretty good but went bankrupt. I started shopping for another callback service and found 2 that had exactly what I wanted: GlobalTel and Telesys. I chose GlobalTel because their Direct Call rates are better and they do not have any minimum per month charge.

Any drawback? No, except that Internet phone is cheaper (but has some drawbacks). Phone calls placed through a callback used the same phone lines and regular international phone calls, therefore the quality is the same as using directly a long distance phone company.