Nokia has started testing a new system that lets mobile phone users tap in to Wi-Fi hotspots as well as GSM cellular networks.

In the city of Oulu in Finland, 50 families will get their hands on Nokia 6136 mobiles in order to try out the new technology.

When a user comes within range of a WLAN network, the phone switches to uses VoIP for low-cost or free calling. Once out of range, it switches back to the GSM network.

Why in particular, has the relatively unknown city of Oulu in the far north been honoured by this test?

Because it has launched a project to enable all of its citizens to receive free wireless internet via hotspots around the city.

The widespread wireless coverage around the downtown area makes it a perfect location for the Nokia trials.