Updated May 2013
Yes, you really can make free phone calls using the Internet! Free internet phone programs let you make free phone calls, usually only to the US and Canada, using special software.
Most of the free phone call applications I list below are PC to phone programs, meaning you can make a free call from your computer to a real telephone number so you don't even need a telephone yourself. Some of the other free internet phone programs will connect your real phone to another real phone for free, making a long distance plan unnecessary.
No matter how it works, it's a free call!
To make a free call using an Internet phone, you might have to download free phone call software or use a soft phone from an Internet phone provider website.
Important: A free Internet phone can not be used to make a 911 or similar emergency call. If you need to call 911, use a traditional land-line or mobile phone, or a VoIP telephone service that's approved for 911 use like Vonage.
1. Google Voice
As of September 2011, Google Voice is the very best way to make free Internet phone calls. With Google Voice, you can make free phone calls, free PC to phone calls (via Google Talk browser plugin), and free PC to PC calls (also via Google Talk).
Google Voice is much more than a way to make free phone calls on the Internet. Google Voice is primarily a way to manage the phone numbers in your life and can be used to intelligently route incoming calls to your free phone number provided by Google Voice to any other phone you have. With Google Voice, you can also get free SMS, make a free conference call, and get free voice mail services.
Free calls you make with Google Voice must be to numbers in the United States or Canada.
Google Voice is available as a web app that you can use in any browser, including mobile browsers (as pictured here). Dedicated apps are available for Android, BlackBerry, and iPhone users.
Free phone calls with Google Voice are limited to three hours. However, you can continue to make a free call to the same number over and over again.
iCall is another tool you can use to make free internet phone calls. With iCall, you can make free calls from PC to phone using their free software.
The computer that you make calls from can be anywhere in the world but for the call to be free, the number you call must be in the United States or Canada. You can't make free phone calls using iCall if you're calling outside the US or Canada.
iCall is available as a free desktop application for Windows, Mac OS X, or Linux and as a free iPhone app. Free phone calls will be disconnected after a short five minutes but you can call the number back again as many times as you want. You will also hear an advertisement before each call that's around ten seconds long.
A flash-based version of iCall is also available on their website but free calls here are limited to three minutes.
EvaPhone is yet another way to make free Internet phone calls. EvaPhone lets you make free, but incredibly short, PC to phone calls all from a Flash-based interface right on their website.
What makes EvaPhone unique is that you can call nearly any phone in the entire world for free. Another thing that makes EvaPhone unique is how incredibly short that free call is. Free calls range from ten seconds to one minute in length, depending on the destination. You're also also limited to just two calls per day.
After dialing a number on EvaPhone, you'll watch a short video advertisement and then your free call will begin. A countdown timer will begin so you know when you'll be disconnected.
I certainly don't think EvaPhone is the best way to make a free call on the Internet, but if you need to tell someone something fast, don't have your own phone, and don't want to pay for the call or download software, EvaPhone might be the perfect free Internet phone for you.
Free PC to PC Phone Calls
I compiled this list of ways to make free Internet phone calls assuming that you're looking for ways to call "real" telephones. However, if you're only interested in free PC to PC calls, several programs can do that.