The apartment that my fiancee and I are moving into after our wedding in December doesn't have a phone line. Living in a college town, almost everyone has cell phones so it isn't really practical for our landlord to have a line installed. This is a little inconvenient for us considering we are poor college students who can't very well afford cell phones at the moment and we don't want long contracts.
I looked at some phone service alternatives and VoIP (Voice over Internet Protocol) seemed to be a good solution considering we do have wireless network access in our apartment. Skype is what we decided to go with.
Skype is an internet phone service that most generally is used by people to "call" each other using their computer's audio and microphone to communicate. The program is free for use over the internet, but using some of Skype's paid services you can use it to replace your current phone line for less than $9 a month.
SkypeIn is a ($18 for 3 months or $60 for 12 months) service that Skype offers which allows you to register a phone number in one of a handful of countries including the U.S. so that people can contact you on Skype from a normal telephone. SkypeIn includes a free Skype Voicemail account.
SkypeOut Unlimited is a ($3 for a month or $30 for 12 months) service which allows you unlimited phone calls from your Skype account to regular telephones anywhere in the country you are calling from.
A combination of these two takes care of all angles of a regular telephone service. The only issue left is implementation. You could implement this using a computer with a heaset just fine, but what if you don't want to have to use your computer to use the telephone? Skype offers some other nifty alternatives to being bound to your computer.
Wi-Fi Skype phone
This device ($100) uses any Wi-Fi connection (secure or not) that is accessible without a browser, to connect to skype. It is portable and allows you to use SkypeIn, SkypeOut, and Skype Voicemail. This is neat because you can take it with you and use it anywhere you have Wi-Fi access
Wireless Skype phone
This device ($150) requires an open LAN port on your router. You plug a base station into your router and then the cordless phone uses Skype in a similar fashion to the above.
Skype has the potential of CD quality sound when you are talking to someone else that is using Skype. When you are talking to someone on a normal phone you are limited to telephone quality. As long as your internet service has semi-decent bandwidth you won't have much interference at all.