Truphone has given the first public demonstration of a VoIP over Wi-Fi phone call on the Apple iPhone.

Chief executive officer James Tagg made the call at the DEMOfall 07 event in San Diego, CA.

Truphone's demo comprised of two iPhones connected to Wi-Fi, a VoIP call, initiated from one handset, routed via Wi-Fi and the Internet to Truphone's servers, and then back again to the access point and onwards to the destination handset, means it was a "100%" IP phone call.

This is particularly significant as Truphone have managed this without unlocking the device - users of the service will be able to execute VoIP calls on a "locked" AT&T (and hopefully O2) handset.

Although just a demo and not a commercial launch of the Truphone service on the iPhone, the company has said they hope to launch to the public soon.

Also demoed at the same event was an application that "mashes up social networking site Facebook and traditional telephony".

Any Facebook user will be able to click on a friend's Truphone "Call Me" button, and a free phone call will be initiated to whichever phone their friend has chosen.

This should mean free calls to real phones for everyone in the Facebook community.

Keep up the good work chaps!