The New York Times > Technology > Circuits > Basics: Internet Phones Arrive at Home (and Some Need No Computer): "Another mobile Wi-Fi phone on the horizon for businesses is Motorola's CN620. It allows business users to talk anywhere inside their offices with Wi-Fi access.
The CN620's most innovative feature, however, is that it also operates on global system for mobile communications, or G.S.M., networks, and automatically switches from VoIP to G.S.M. when a user strays beyond the range of a corporate Wi-Fi network. Its sound quality is at least as good as that of a regular phone. The CN620 should be ready for home offices later this year, and probably for regular consumer use by next year, according to Proxim, a Motorola partner involved in testing the phone."