LinuxDevices - Software turns mobile phones into walkie-talkies:
"Esmertec is shipping software that adds real-time push-to-talk functionality to 2.5G and 3G mobile phones. The u@PoC (Push-to-talk over Cellular) client allows users to establish one-on-one or one-to-many (group) conversations, and can be ported to any platform with a C compiler, the company says. "
