The New York Times writes:
What if, instead of burning up minutes on your cellphone plan, you could make free or cheap calls over the wireless networks that allow Internet access in many coffee shops, airports and homes?
New phones coming on the market will allow just that.
Instead of relying on standard cellphone networks, the phones will make use of the anarchic global patchwork of so-called Wi-Fi hotspots. Other models will be able to switch easily between the two modes.