Wi-Fi Everywhere May Let You Roam Free From Your Mobile Carrier To get the most out of your smartphone do you really need a cellphone plan? That's the question Wall Street Journal reporter Ryan Knutson tried to answer recently when he spent a month relying only on Wi-Fi networks for his mobile data and voice needs.The results: By making some sacrifices and adjustments to your routine you can get almost as much out of your smartphone with a monthly bill of $0.The frustrations of the switch were relatively minimal Knutson told NPR's Robert Siegel in an interview conducted over Skype.One thing I normally call my mother as I'm walking to the subway each morning but with Wi-Fi they're hotspots Knutson said. So you can't walk down the street or drive in a car while doing the Wi-Fi only plan because the signals just don't carry far enough to cover you over long distances.There are companies lining up to help you make the switch - an app to help you find nearby hotspots even if you're offline companies stitching individual hotspots into networks and carriers with cheap plans that rely on Wi-Fi first and roam on the network of a cellular provider such as Sprint as a backup.Google on Monday announced its own plans to enter the cellphone carrier market The New York Times reported:The ease of his transition and the burgeoning competition could pose serious issues for the industry Knutson writes:Knutson told Siegel that cellphone providers aren't worried about the competition saying there always will be a market for people who will pay money to have connectivity wherever they go but that the pattern fits into one described by Harvard Professor Clayton Christensen in The Innovator's Dilemma - a low-cost low-quality alternative that slowly improves until it has claimed the bulk of an industry's customers.