I've just started using VOIP, otherwise known as Voice over Internet Protocol, otherwise know as free telephone calls!!!
I'm using Skype at the moment. It gives you free phone calls for all calls between Skype customers, and you can also call normal (BT) phones for less than the normal BT rate.
I have a box which is basically a sound card attached to the usb port, which can have an ordinary phone plugged into it instead of a speaker and microphone. To make it work as close to an ordinary phone, it needs special software to detect whenever a button is pushed on the phone, and send the correct signal to Skype. I'm using the free code from two places :