I cancelled my
Vonage service today; though I was initially quite taken with the phone-via-internet service, I just found that I wasn't using it at all, especially with my wife in Texas with the equipment. Truth be told, we really hadn't used it much for the last six months, and then only to buzz one another at home when we left our cell phones in some corner of the house where we couldn't hear them ring. Cap that off with the fact that you can't dial out via Tivo or fax or modem (not that you need to use a modem with high-speed internet, but you know what I mean) over a Vonage line, and it was time for the service to go.
Still, if you like the idea of having a "home" phone as opposed to complete dependence on your cell phone, and you have a high-speed net connection, Vonage may well help you save a nice chunk of change each month.