Erik writes:
> Oops, I think the comment about the code being there a million times was
> erroneous. Just the data is serialized. You need the class file
> somewhere too.

I'm pretty sure you can send the class file too if you want to, so
completely mobile code and data are possible with standard Java.  RMI will
transport the class files along with classes if needed for example.

IBM has a project to produce mobile agents written in Java.  These "Aglets"
travel around the network taking their data and code with them as they go.

   http://www.trl.ibm.co.jp/aglets/

G.