I recently joined ntl: for my internet access.
On a BT phone line I pay 10 quid pm for 24/7 access. The package includes 10 quid worth of phone calls at ntl: rates (approx 1 p /min less than BT but plus a 3.5 p connection fee).
There is also a one-off charge for a telephone line adapter that automatically routes all calls through ntl:'s network.
My connection averages slightly faster than I was achieving with Virgin.net. ntl: say that their internet access is a completely separate digital network. Presumably this accounts for the slight increase?