No!!! Definitely I am not very keen on installing non-free packages. However, my thirst for learning about new software is greater than you might imagine. I needed to try Desktoptwo for a review article I was writing and obviously I was asked to install Java (and also Adobe Reader) to run the software.
Installing the Java runtime environment in Lenny is a blast. You only have to enable non-free in your sources.list file. Run apt-get update and apt-get install sun-java6-jre. And you get a neat and clean installation. However, it will not be enough. It will not work. If you run Sun's Java, your jre will not be detected.
The tip and trick is installing the sun-java6-plugin which allows Mozilla and other browsers to use the java plugin. Java Plug-in comes with the Java Runtime Environment (JRE). Just run apt-get install sun-java6-plugin and you are done.
By the way, desktoptwo is okay. I like it but I still prefer eyeOS.
Here is some more information quoted from the description of the packages.
*Sun Java(TM) Runtime Environment (JRE) 6 (architecture independent files)
The Sun Java Platform Standard Edition Runtime Environment (JRE) 6
contains the Java virtual machine, runtime class libraries, and
Java application launcher that are necessary to run programs written
in the Java progamming language. It is not a development environment and
doesn't contain development tools such as compilers or debuggers.
For development tools, see the Java Development Kit JDK(TM) 6
NOTE: You must accept Sun's EULA prior to successfully installing
This package contains architecture independent files.
*The Java(TM) Plug-in, Java SE 6
Java Plug-in enables applets written to the Java Platform 6
specification to be run in Mozilla and other web browsers.
Java Plug-in comes with the Java Runtime Environment (JRE).
This is a metapackage containing dependencies for running Java in