My brother, Matthias, just told me about Skype which is an excellent (and free!) software, which allows you to do free phone calls through the internet - all over the world.
I tried it out and was really surprised about the good quality and easy handling.
What can I say more, the slogan "P2P telephony that just works" is definitely right.
Here are some features of Skype:
* Free unlimited worldwide phone calls to other Skype users
* Superior sound quality - better than your regular phone
* Works with all firewall, NAT and routers ? nothing to configure!
* Friends list shows you when your Skype friends are online and ready to talk or chat
* Super-simple and easy to use
* Your calls are encrypted "end-to-end" for superior privacy
* Based on cutting edge peer-to-peer technology developed by the creators of Kazaa and Joltid