Depends on the number. If it is an international skype number then yes, you are charged for international calling. If they gave you a US type number to call but are located outside the states then it is counted towards your normal minutes.
For example, my brother was recently stationed in Korea. Thanks to him having a skype account he created when back home, we were able to call him on skype using a Virginia number (757 area code). Saved us lots of money and headaches.
Calling skype uses your normal minutes unless you add it to your friends & family.
