My Company has used a product calle HearME VOIP (Voice Over Internet Protocol) for 5 years now.
Unfortunately the company went belly up but has sold the technology to various companies and universitys.
We are using it to give online classes all over the U.S.
This product uses a protocol called SIP (Session Initiation Protocol)
It seems to be a more robust protocol than what other VOIP providers use, Which are called H.323 and some other ones I am not familiar with.
Now that I have bored you with some of the technical stuff.
Lets talk about company's.
I had a customer of mine use something called Epals?
She uses it to call her friends and family in Panama
ocassionaly she has to use the chat feature because the VOIP would crap out on her. But hey, she was happy and she was able to communicate with her Mother to tell her she is alive an well.
Here is another company that seems to be making some waves.
you may have to install some spyware with it, but read the licenses agreement carefully.
Yahoo messenger has a VOIP product built into it. I have used it but it takes some skill for the other person on the recieving end to set it up.
IP telephony is still in it's infancy. Allthoguh I have used it for 5 years now, it's only recently (2 years) that it has taken off.
Your voice quality will vary depending to who and where you are talking to.(Thier internet connection and what equipment thier ISP uses.)
If you stick to the U.S. you won't have much trouble. You'll have an ocassional moment of silence but I think you will be able to get your point accross.
You have to weigh the cost versses reliability.
You are venturing into the bleeding edge of technology.
You have to ask yourself, if they are offering free VOIP how are they making any money?
I heard just recently that a court ruled that Vonage was considered a phone company. So guess what, that means surcharges to 911,homeland security,My sisters dog's vet appoitment and other BS taxes are comming real soon.
If you are considering using VOIP for business you have to ask yourself, is every 4th word in your conversation "Can you hear me now" worth the aggravation?
On a non related note.
I went to a computer dog and pony show last year an ran into a lot of VOIP vendors. Most of what they were selling was pure crap. There was a company whos name escapes me who had a really sweet turnkey product.
The VOIP phones start arround $250.00 a pop.
CISCO sells a VOIP system, which is supposed to be a turn key system.
But a company they were doing business with told them to remove the phones and all thier equipment because it did not work as advertised.
6 months of headaches so they went back to a standard digital phone system.