I've hacked up an implementation of using openDHT using Java. works pretty fine so far using standard XML-RPC.
Might not be the best code, but I sure as hell could have used something like that :)
Ryan Worsley did lay the foundation, but I never could get his code to run on my Java 1.5 + Eclipse Configuration, so I hacked it to a working level and wrote a little "tester"; app.
have fun :)