I saw no notice of this anywhere, maybe I missed it. One of the great features of recent Nokia smartphones (Nseries) is that they are Wifi-enabled as well. Hence, instead of paying heavy data fees, you can switch to a wifi network and surf the net, upload videos / pictures, watch videos, call using Voice over IP, etc.
But configuring a wifi access is cumbersome at best, complicated usually.
FON is buiding a global network of wifi coverage. Logging onto a FON network was complicated on a phone. The problem is now solved on most phones I use, as they've developped a little app that makes it so simple to login to a FON network.