http://news.bbc.co.uk/1/hi/technology/3791319.stm
Pretty forward thinking from BT here...
BT is planning to rebuild its phone network in the UK in a radical move that will cost billions.
It could change the way people use their phones and allow most people with a BT phone line to plug into broadband using computers, mobiles or other devices.
It could also mean that mobiles and fixed lines become interchangeable, with the same number and bill.
BT plans to convert the majority of its customers to the new network by 2009.
Dubbed the 21st century network, the technical work requires a gradual closing down of the old Public Switched Telephone network (PSTN) to make way for an internet protocol (IP) network.