Forbes has an article by Clay Christensen and others:
The combination of the dramatic growth of new wireless Internet access technologies such as WiFi, the ability to use Voice over Internet Protocol (VoIP) to make voice calls and the potential rise of companies willing to give away wireless service makes disruption a real possibility.
What happens if companies go beyond charging a low flat rate that undercuts wireless carriers? What if they actually give away wireless voice and data service?
Free wireless access for all may be the wave of the future. In January 2006, serial entrepreneur Martin Varsavsky launched FON, an open WiFi community where members agree to share their broadband Internet connections through WiFi access points in return for the ability to use the WiFi access points of other community members. Just one month later, FON received financial backing from Google, Skype and a number of prominent venture capital firms.