Bill Joy, Sun Microsystems’ co-founder and chief scientist, pitched Sun’s new JXTA peer-to-peer networking “core architecture” at the JavaOne conference.

A new JXTA app called the PeerSwitch “turns clients into routers” — people running this program can give others access to content they’ve downloaded from the Web.

Thanks to JXTA, the Sun execs said, we’ll soon be seeing hordes of peer-to-peer Java programs available on the Web.