If the other end has a computer, Skype to Skype is the only way to go. Or do it on a smart phone with wireless connection if available.
I also use Lyca for my overseas calls. Great for convenience, just buy a sim card ($2.00) at many locations. Buy the credit from same places.
Call charges from 3c a minute all over the world, plus a small connection fee.
It is similar to Skype, as it uses internet for calls, but convenient as you can use it with a Mobile phone.
I use it regularly, when partner goes overseas and find it very reliable.

Greg