I have been a past Skype user, once had an account with Vonage, and have dabbled with Google Talk and other peer-to-peer services. I never was thrilled with Skype even when it was free, became disenchanted with Vonage, and have found many of the free online options lacking in usability and sound quality. Free is not much good if you cannot hear the person you are calling, or you get disconnected.
I am not the proud owner of an iPhone, doubt I ever will be...but am impressed with the fact you can make free calls when you combine JAJAH with your iPhone. You also can make free calls using JAJAH and any other cell phone or land line phone. JAJAH is my current favorite for the quality and flexibility. To make it free, both parties to the phone call have to have joined via the JAJAH website.
For other options go to Free International Calls to see YouTube Videos on Rebtel. Fring, Jaxtr, and others. Go to Voip-Sol Dot Com for 10 Skype Alternatives with links and reviews.
Runner up for me right now is Yoomba, thanks to Phil Butler. This uses your email account to enable free voice calls and requires a download.
To use Yoomba, you will have to be near a computer with an Internet connection, and a headset or USB phone (I use a Skype enabled USB phone). Go to Yoomba Dot Com to get your free download and activation.
Lot's of choices, and not all will survive or remain "Free"...but it should keep getting better and more competitive. As an aside, Google has acquired a service named Grand Central. If you happen to be a beta tester, The Digital Nomad would appreciate an invite to the beta test.
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