I've been a Vonage subscribe for over 5 years now and I've been very happy with their internet based telephone system. Basically if you get Vonage you don't need a phone line, just an internet connection. When you sign up they send you a little box you plug in to your network to which you connect any standard telephone. Once you plug everything in you get nation-wide long distance for free for about $25 a month or you can get a 500 minute plan for $15 a month.
You can transfer your existing telephone number to it or get a new one. It's just like your normal phone service, but has some other cool features like the ability to simultaneously ring your cell phone and your home. You can also get a soft phone that you can use on your laptop from anywhere that has internet access. Right now they are offering 2 month of free service for both you and me if you sign up [click here to do so].