Remember When Phones Were Walkie Talkies? - YouTube
Nextel makes leap into 21st century
It's no accident that Apple chose a yellow icon for its walkie-talkie feature. I dug out my old (2002ish) Nextel with PTT (push to talk). It was all the rage back then... :
Motorola Nextel i355 Direct Talk - Walkie Talkie PTT | eBay