A Madrid-based software startup called Fon has attracted $21.7 million for what its founder, Martin Varsavsky, described as "a global network of shared Wi-Fi connections," reports the New York Times. Google, Skype and venture capital firms Sequoia Capital and Index Ventures are among the investors. The service allows subscribers to modify their routers so that Wi-Fi users can connect to the internet at many physical locations. Mike Volpi, Cisco's VP of business development, and Niklas Zennström, a founder of Skype, will join the Fon board.