Push-to-talk, or PTT, is an increasingly popular service that lets mobile phones serve as walkie-talkies, but without the distance limitations. Using PTT means cellular subscribers don't have to make a call every time they want to talk to someone. They also don't have to keep a minutes-devouring cellular connection open if the conversation consists mainly of brief exchanges separated by long silences. All they have to do — as the name makes clear — is push a button and say what they need to, and the other person hears it.
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