Ok, so firstly, credit for this goes to Cara for being a nerd and finding it before me!

Skype is amazing! I called Cara yesterday on it and it is as clear as any phone! and you can play in the chat window while you are talking and send each other silly emoticons and stuff....... it's really good and way better quality and easier to use than msn messenger as it's actually a phone program.

Also for international calls I think it would be extremely cheap.... similar to those calling cards but without the hassle of having to buy them and enter pin numbers etc..... wow!