At the heart of this issue are some brand-spanking-new technologies and some new twists on older technologies that converge high-speed landline and wireless Internet access with VOIP. These technologies enable VOIP, which is already a reality in many homes and offices, to become mobile.

The furthest along of these emerging wide-area wireless technologies are wide-area Wi-Fi mesh networks, which proponents claim can cover entire metropolitan areas. Cities such as Philadelphia have received the lion's share of attention about their citywide mesh networking plans, but this technology is already in place in a number of smaller cities.

Some believe that citywide Wi-Fi alone will change the mobile voice landscape, opening the way for increased adoption of mobile VOIP. However, others, such as Phil Redman, a research vice president at Gartner, don't believe Wi-Fi mesh is up to the task.

"One big reason municipal [Wi-Fi] services will fail is that there's no control," Redman said. "This is unlicensed spectrum, so if I blast you with my private networks, there's nothing much you can do about it."

Also, he noted that the current Wi-Fi standard doesn't have built-in quality of service to ensure voice quality, an issue that will be resolved when the next Wi-Fi standard, 802.11n, is ratified later this year or early next.