While the focus is on the Big Four cell operators, don't discount Alltel, which has unlimited EVDO and now a Wi-Fi plan: Alltel is a smaller carrier but a significant one because it owns licenses and operates EVDO service in areas that Sprint Nextel and Verizon don't cover. This complementary access allows Alltel to offer unlimited EVDO on a national basis using the other carriers' networks as backup and still price it at $60 per month with a service commitment. Their addition of Wi-Fi tacks $10 on per month if you're already an EVDO subscriber.
Alltel is reselling Boingo Wireless's network, and pricing it on a walk-up basis at $22 per month for unlimited domestic U.S. access, just as Boingo itself offers.
This is rather enlightened, I must say. AT&T treats its consumer division AT&T WiFi network like a red-headed stepchild (no offense to red heads or stepchildren)and Verizon and Sprint offer Wi-Fi with a bit of disdain. T-Mobile, with its lack of 3G service, is the only cell carrier to take Wi-Fi seriously because it has to.