I have been registered with VoIPSTUNT for 5 months now. To my understanding they are one of the best VoIP providers I have seen. I have used this company many times everyday, and they are simply wonderful. I have a laptop 4 years old without any upgrade in the hardware. The VoIP has run smooth and without any problem every time I have used it. I have an USB VoIP phone that cost me 20 USD, and I can dial directly from the phone or from the software program.
You can go to www.voipstunt.com and take a look yourself. They have a lot of countries worldwide where you can make free calls, such as Australia, Canada, France, Germany, the USA (mobiles included), and many other countries. In my opinion, VoIPSTUNT is one of the best VoIP companies you can join for free. If this seems too good to be true, just type http://www.voipstunt.com and check it out.