IP Messenger for iPhone enables to send and receive messages through UDP/IP via Local Area Network.
You don't need to register a receiver's contact. As soon as this application is launched, a new IP Messenger user will be found automatically through Local Area Network.
The original software has been transplanted to Mac OS, Java, X11R6, and you can send the message beyond platform.
Windows version can be downloaded from here
IP Messenger Research & Development (http://ipmsg.org/)
Device: iPhone, iPod touch, iPad
Minimum OS Requirements: iPhone OS 3.1.3