Dedicated answering and VOIP number

Hi, I have recently had a relative visit from north america, who brought his IP phone with cisco hardware provided by http://www.vonage.com with him, and it works very well, allowing him to make and receive calls to N.america and canada for free, and receive call dialed to a normal US number. I am after a similar product/service in the UK, perhaps with a telephone answering assistant that will direct calls to people within my small company, any ideas?