The testing is being done using Earthlinks Muni WiFi system in
"What separates our Wi-Fi phone from others is its ability to work over EarthLink's municipal Wi-Fi networks," said Steve Howe, EarthLink's senior vice president of voice. "This means that EarthLink is now bringing cheap phone calls using the Internet to the world of mobile -- a major breakthrough. We expect that many people who use cell phones today in our municipal Wi-Fi markets will want to switch to a Wi-Fi phone to take advantage of the significant cost savings." He added that EarthLink's Wi-Fi phones round-out the company's full suite of Internet voice products, which also include trueVoice, a low-cost telephone service, and DSL and Home Phone Service, which combines low-cost phone service with ultra-fast high speed Internet.
In addition to Earthlink, T-Mobile has been testing their HotSpot @ Home service in
Systems that provide both cellular and WiFi connectivity in one device make a lot of sense to me because they allow the user to have a single phone with a single bill.