I could write a hugmongous post about the logarithmic advancement and adoption of technology but suffice it to say that things are moving quick these days. Right around the corner are cell phones that seamlessly switch between a cellular network and VOIP over WiFi -
mid call!
Cell Phone Industry Steps Closer to VoIP:
Wojtek Felendzer held a mobile phone to his ear as he walked across the room, the call automatically switching behind the scenes from a Wi-Fi wireless hotspot to the regular cellular network.
"Can you still hear me?" the Nokia Corp. employee asked.
"Yes," the reporter answered.
"That's good," he said. "This is seamless handover. The voice didn't drop. Nothing bad happened."
It might be a year or more away from reality in the market place but that's an awful quick transition if you consider how old all of these disparite technologies are.. WiFi, Cells, and VOIP (hint: not very old).