I work in Indonesia at the moment, but about to move to Quatar.

We use Skype for most of our international calls.

1.- Skype-to-Skype (computer-to-computer) calls are free and if you have enough bandwidth on both ends, you can do video calls too.

2.- Skype-to-phone service costs money and Skype needs a credic card number on file, from which it draws an equivalent of 10 Euro or 10 USD dependingon you account setup, whenever the balance dips below 2 Dollars or Euro. Assuming you have a credit card, use this because the rates are ridiculously cheap ($0.02-0.05/minute for most landlines anywhere in the world, $0.18/minute to call most mobile phones anywhere in the world).

3.- Phone-to-Skype is another cool feature. You buy a land-based number from Skype say in Germany or in the U.S., and your family/friends back home can call that number to reach you without making international calls. The call gets routed through the Skype network to your PC and, if you are logged in, it rings. Your account gets charged the Skype-in rate (cheap, same as Skype-to-phone). Better yet, you can set up forwarding to a phone number. If you don't answer Skype, the call gets forwarded to any number in the world, which can be your Quatar mobile. Your account is charged the Skype-out rate (cheap) and you completely avoid dealing with the local long distance phone company.