I have it -- it's awesome.
I live in Florida but have an Illinois phone number so my family up there can call me at no cost to them -- it's a local call to them...and it costs me nothing extra. They just don't "get" that LOL
Vonage has a feature called Simul-Ring -- when someone calls my Vonage phone number it will ring (I think) up to 8 additional phone numbers I want. I have it set up to ring my cell-phone simultaneously. But I can have it ring ANY phone numbers I choose.
If you travel...just take your phone modem and plug it into a high-speed line and you have YOUR phone service. They say this is true no matter where in the world you might be plugging it in.
Toll-free numbers are only $5 a month and that includes 100 minutes of talk time. I think it's only 5 or 6 cents a minute after that. You can also get additional phone numbers in any location they have numbers available so you can have a multitude of "home phone numbers" that will all ring your one phone line.
Like I said...it's way cool and I am happy with it. People who think it sucks need better high-speed Internet service
I have RoadRuner that d/l's at 8 MegaBit -- I have no problems with Vonage no matter what I am doing online. But when I griefly had DSL -- Vonage was PURE SHIT...not Vonage's fault.