The official release of Skype 1.0 provides added functionalities including integrated PC-to-phone calling to any landline or mobile phone in the world and direct P2P file transfer among Skype users on any computer platform (for now Windows and Linux. Mac coming next). Outside of a poor user interface that needs still lots of improvements, Skype offer quality voice over IP communications between two or more PCs at absolutely no cost. To tap into the PC-to-phone capabilities you need to prepay your preferred amount and then you can immediately start calling any telephone number in the world directly from your PC or Linux machine. Quality of voice is particularly good, though you need to be on a high-speed Internet connection (ISDN or better). Calling some mobile providers may not turn always into successful exchanges and there is still a good dose of thrill in making each call go through. But overall, and given the unbelievable rates offered (I have spent 0.68 USD for a 23 minute call between Rome-Italy and a small village in Patagonia-Argentina) this is a must-have communication tool. Highly recommended. Read more about it.