You can make a free phone calls to landline phone from your computer through the internet. You must have a broadband connection to get maximum quality of voice. This is a list of VoIP softwares you can use to make a free phone calls from your computer.
Skype
Skype offers free PC to PC calling as well as inexpensive PC to Phone service. From the makers of Kazaa, Skype utilises Peer to Peer (P2P) technology for carriage of its voice traffic
www.skype.com
Cliconnect
Cliconnect offer terrific rates as well as SIP compatibility. No start-up fees, no monthly fees, no commitments. Also have comprehensive setup instructions for a variety of SIP based VoIP hardware
www.cliconnect.com
Peneo
SIP compatibility, Callback service and low calling rates. USA 2c/min, China 2.4c/min, Russia 2.2c/min, Vietnam 2.42c/min
www.peneo.com
GlobalVoiz
GlobalVoiz is a leading worlwide PC-to-Phone provider that offers a next generation communication tool that enables calls from a PC to either a fixed line phone or mobile phone, whether in a dialup or broadband environment. Offer both browser-based and Windows-based softphones.
www.globalvoiz.com
RingAsia
Rates are accessible by clicking the small arrow icon in the top right-hand area of the landing page. RingAsia offer a Windows-based PC to Phone softphone as well as a web browser based softphone. May also support SIP.
www.ringasia.com/pcphone.php
CallPacket
CallPacket have changed the rules on what to expect from a VoIP service Provider. They currently have an amazing promotion whereby you can get a real, free telephone number, 100 free US long distance minutes per month and more. SIP compatible
www.callpacket.com
VBuzzer
Terrific rates, real Canadian PSTN inbound telephone numbers available. Free, unlimited PC to PC calls. 1c/min Promotional rate to 20 countries expires (Dec 31st, 2005)
www.VBuzzer.com
BlasterPhone
High Speed Internet Connection required (e.g., DSL/Cable). BlasterPhone uses SIP technology and hence supports both 'softphones' (PC to Phone) and VoIP 'devices' (ATAs, IP Phones, etc). Rates to the US and Canada start at 2.2 c/min. Mexico City 3.5 c/min, China 2.9 c/min, Bangladesh 6.2 c/min
www.blasterphone.com
BeyondPhone
US/Canada from 2 c/min. Supports SIP for 'Device to Phone' applications. India (Fixed lines) from 20.1 c/min. Pakistan 26 c/min. Free 'in-network' calling
www.beyondphone.com
Efonica
PC to Phone calls, web initiated Phone to Phone calls, India 23c/min, USA 2.9c/min, Pakistan 32.9c/min, UK (London) 3.9c/min, Germany 3.9c/min, Spain 6c/min
www.efonica.com