Walkie-Talkie
A type of personal 2-way radio, usually hand-held, that unlike a cell phone, operates independently of any land-based network. One user can speak instantly to all other users within range by simply pushing down a "talk" button.
Functionality similar to a Walkie-Talkie has also been duplicated on cell phones, in the form of a service called Push-To-Talk (PTT).
See: PTT
