Sprint's iDEN network may have just recently shut off for good, but push-to-talk (PTT) technology isn't gone. Today, Motorola launched PRIP -- a PTT platform that works using mobile data or WiFi networks -- in the US, after launching the service in Mexico in April. For stateside residents, PRIP's available as a download from Google Play now, provided their phones are running Android 2.3 or later, with an iOS version arriving in the coming weeks. For now, folks who sign up can use the servic
