The Javamorph project can be found at Google Code or if you’re lucky enough to use Ubuntu it’s in your repositories so you can just apt-get it. I think it’s in the Debian Squeeze repos too.
The project homepage is worth checking out for a brief overview of how the program works and a link to a very informative pdf that explains all.
My very quick and dirty example shows me turning into my youngest brother and back again. Sorry Sam.