A WiFi phone is a wireless telephone that looks similar to a mobile phone but
places calls via a combination of voice over IP and WiFi rather than via a
cellular network. Current WiFi phones use Skype or Vonage for their voice over
IP service. To compete with WiFi phones, several cellular carriers have created
"Dual-mode phones", which can be easily switched between using a WiFi connection
when one is available and a traditional cellular network connection when WiFi is
not available.
