You can call skype-to-skype, which is totally free. You can also get 'skype out', which is where you buy credit from Skype: You can then call landlines and mobile phones and they will charge your credit. I bought 10 euros worth of credit years ago and I'm still not out. Calling landlines is very very cheap, it doesn't matter much where in the world it is (you can check the prices on their site). It's slightly more expensive to call mobile phones. If you don't need to call a regular phone for a while then you must remember to do a one-second call to a phone (say, your own one) inside 6 months or you will lose your credit. Skype will email you a reminder in advance.
The imagination consoles people about what they cannot be and the humor about what they actually are. -Albert Camus