If you make a lot of international phones calls, or even if you don’t make a lot of them but need to be flexible in how and when you make them, running an Asterisk server could be the way to go.
Asterisk is a OpenSource telephone system that runs on top of Linux. Asterisk can be quite difficult to manage as it involves editing text based configuration files. If you don’t want to do this you can install a web based management interface called FreePBX. This provides lots of management functionality from a nice web based GUI.
Here are just some ideas for how you could use your own phone system –
Cheap calls abroad from your cell phone
Asterisk/FreePBX provides a feature called DISA. This enables to dial into your Asterisk server (via a local access number available from an ITSP such as CallWithUs) and then dial back out again (again via an ITSP). This would enable to call anywhere in the would at a local rate, right from your cell phone.