One of my main interests is Voice over Internet.  If you have high speed Internet (HSI), you can leverage inexpensive phone service.  I personally have not had a Plain Old Telephone System(POTS) since 2004.  I began with iConnectHere.com, then Vonage, BroadvoxDirect.com, Vonage(again!), Packet8.net, and currently use VOIPo.com