I recommend the magicJack if you want unlimited long distance calling anywhere in the United States or Canada.
I have a Mac Mini that is connected to my TV and runs all the time. The magicJack is plugged into one of the USB ports. Any standard phone plugs into the magicJack. If you're using a cordless handset, it shouldn't matter to you that the base needs to be somewhat near the computer.
If your computer isn't running, you are on the phone or don't answer, or you choose to ignore an incoming call, the call will go o to voicemail. Your voicemail is stored online so you can access it from anywhere. You will also receive an email with a .wmv file attachment of the voicemail. You can delete them from your voicemail account, but store them in your email if you like.
Caller ID is included!
You choose your area code and exchange after you receive the magicJack and plug it in for the first time. It wasn't until then that I discovered that there are no 603 area code numbers available (New Hampshire). Vermont is available - go figure! I grew up in Massachusetts, so I chose an area code and exchange near my hometown.
I recommend the magicJack primarily for making outbound long distance calls. I'm not keen on using a permanent number that is out of state. For less than twenty dollars a month, I keep my regular landline number for in-state calls and I don't have to change my number. The magicJack Frequently Asks Questions indicates that "someday" you may be able to transfer your number. I'm not holding my breath.
For $19.95 annually for the magicJack service, it's well worth saving cell phone minutes when making calls from home. You can purchase five years of service for $69.95, but I'm going to wait a while and make sure I really want to use this indefinitely.
You register your magicJack number with 911 through the magicJack software, so no risk there.
Take your magicJack with you when you travel with your laptop. Plug the hotel phone or borrow a phone and make long distance calls for free!
International long distance plans are available for an additional charge.
The day I can replace my magicJack number with the landline number that I've had for years, is the day I will get rid of my landline forever. In the meantime, I still recommend the magicJack.