Make free calls to your friends and family living in USA,Canada and UK

Hey guys I have found a couple of websites that allow you to make free phone calls to the people in USA, UK & Canada and the best thing is that the number of calls you are allowed to make are unlimited.Well as you Google about making free calls to phones using your PA,a bunch of results pop up.Most of them needs you to install their software for making free calls like the software from www.mediaringtalk.com and www.icall.com etc….There are some other websites which allow you to make calls without installing any software like www.evaphone.com and www.callingamerica.com
Here are the websites:
1.evaphone:
Allows you to call to any country,but the calls you can make are limited.For more details visit the website.
2.callingamerica:
Allows you to make free calls to US and canada.Calls you can make are unlimited.But every call will be cut after 15minutes.For more details visit the website.
3.mediaringtalk:
Allows you to make free calls to UK,China,Singapore,Australia,US,Canada,But you have to install their software.For more details visit the website.
4. http://www.mobivox.com
People in countries other than INDIA can use the websites given below.I haven’t tried them as they doesn’t support the country(INDIA) where i live……
http://www.youcall.com/en/
https://www.gorillamobile.com
http://www.tokiva.com/
http://www.vivophone.com
http://www.goobercall.com/
http://www.sendglobal.com
http://www.dialsimple.com
http://www.flashphone.ru
http://www.iamvoip.com
http://www.rebtel.com    -10 minutes of free call
http://www.talkety.com
http://www.voipax.com
There are websites like the www.gizmocall.com & few others which say that they allow free calls worldwide. But none of them worked out for me. Most of them want the users to get registered to make free calls.