Vonage - Service Provider
Vonage is a complete VOIP solution provider. They only have paid services, but offer a much more versatile product and service. You don't even need a pc, you only need a high speed (broadband) internet connection. You can use any standard phone with the Vonage service, they send you a free adapter to plug a regular phone into your internet connection.
Their premium unlimited service runs less than 30 dollars a month, and includes unlimited calls to anywhere in the U.S. and Canada. International calls are extra.
There are no special numbers or codes to remember, just dial with your phone as you would normally. Free features include voicemail, caller id with name, call waiting, call forwarding, 3 way calling, and many others. You can even take your phone with you when traveling and use the Vonage service from another location with a broadband connection.
Visit Vonage for more information.