Nextel, a division of Sprint, makes rugged push-to-talk phones, ideal for use on the job or for those interested in saving their minutes using the walkie-talkie functionality. The best Nextel phones are easy-to-use, unbreakable and perhaps most importantly, offer loud and clear voice quality. The BlackBerry Curve 8350i for Nextel is the only BlackBerry with push-to-talk functionality.