JMingle is a social networking endeavor that works by scanning phones over Bluetooth. The goal of the project is to create a social networking platform in which ‘links’ between people are created when they are in range for their Bluetooth-enabled phones (or, eventually, other devices) can discover each other.

Future goals for JMingle are to create a more “competitive” style where those with the most “bump-ins” are ranked on a centralized site. This would require a web site where accounts are attached to the unique Bluetooth addresses of each device.

http://code.google.com/p/jmingle/