Where ISN'T there a WiFi signal?
My first caffienated brain-burp of the day:
1. Set up VPN VOIP Proxy in a free country. (Sweden?)
2. Produce clients that allow a person's wifi phone (or even bluetooth if you can get the range) to access said proxy for a small fee, via their wifi access point.
3. Allow owners of said access points to share their connection (i.e. just to the proxy) with the members of said proxy, for a cut of the proxy access fee.
4. Profit! :-)
I'm not suggesting this would work everywhere, but it could start with airports, train stations, city centres, petrol stations, supermarkets. Anywhere people would stay within one WiFi network while chatting.