Screaming Penguin - Source Does Matter

JXTA is a psuedonym for the Java "juxtapose" project which is designed to enable network devices of any kind to intereact in a P2P manner. The official definition is "JXTA technology is a set of open protocols that allow any connected device on the network ranging from cell phones and wireless PDAs to PCs and servers to communicate and collaborate in a P2P manner."

The first part in an Oreilly book excerpt series is available via the link. Its a good tutorial and JXTA is definitely interesting stuff.   Getting Started with JXTA, Part 1: Oreilly