Is VoIP the right phone solution for me?

How do I know if VoIP will meet my calling needs?
I’ll preface this by saying, if you’re using a dial-up Interet Service Provider,VoIP is not for you because it’s too slow to get good call quality and you’re accessing the Internet over your current phone solution anyway. Order of importance of these 5 things may vary from person to person. All of them come into play at some level for any calling plan, from traditional landline service, to cellular service, to VoIP. Find out if VoIP will work for you.
There are five key points to determining whether VoIP meets your phone needs:
Service needs to be reliable.
Phone service is something we count on being there when we need it. When the power goes out, unless you use a powered phone, you can pick up the receiver and get dial tone. This is a comforting feeling, knowing you can reach people in an emergency. VoIP can’t provide that level of reliability yet, unless you have a backup generator on your property. This isn’t as vital with the prevalence of cell phones, but still a concern for some people. For VoIP to work reliably your power company and ISP must also be reliable. If either have frequent outages or frequent seasonal outages due to storms, VoIP may not be your best choice for phone service.
Sound quality needs to be exceptional
Cell phones are the one technology that we seem to accept poor service from. Calls still routinely drop and there are major dead areas with no service in many parts of North America. For VoIP, we rightfully create landline service expectations right down to call quality. If you try a VoIP service and get latency don’t use it unless the service is free. Vonage and VoicePulse both deliver great call quality that meets or exceeds landline service.
Hardware requirements need to pass the spouse test and the newbie factor
This one is a little vague, but unless your spouse is a geek, he or she will not want to plug in a USB headset or handset and talk at the computer. Fortunately most VoIP services now offer alternatives that mimic or are landline phones. I chose Vonage for my home service specifically because I could use a traditional phone to place and receive calls.
It needs to be easily portable to a new residence
While cellular service is more portable than either landline or VoIP service, VoIP is a close second. In the case of my current Vonage setup, I can disconnect the Linksys Phone Adapter from my home network, connect it to another network and bring my phone number with me. Unlike landline service, I won’t get charged a fee for the privilege of keeping the same number when I move from my current residence to a new one. Even better, for an extra fee Vonage will provide me with a second number in another area code for $4.99 per month, which might be attractive for people like me who live in one state and have family in another.
Pricing needs to be affordable
For me, this is where VoIP made the slam dunk. I get all the calling features of a landline phone service, including call waiting, caller ID, call forwarding, and 3-way calling, as well as services like *69 that a traditional phone company might charge for. On top of traditional phone services, I get voicemail delivered to my email or to my cell phone and cool features like Click2Call from Vonage that let me select a number from my Outlook contacts and pre-load my phone to call the party without ever dialing. The price is more attractive than any landline service I’ve had in the last five years, with the added bonus of free long distance.

Many of the references I make here are in regards to the Vonage service, but similar features are available with most other commercial VoIP phone service providers.
Other VoIP related articles:
Will VoIP Work with DSL?
VoIP over Home Phone Wiring
VoIP Disaster Recovery Planning
Cellphone to Landline Converter