For a while I've been using the XMLmind xml editor to write documentation for the RIFE project in docbook. I've been very impressed with how easy it is to work on the users guide after having done documentation before in raw docbook with XEmacs.
Today I started to get really annoyed while editing javadoc comments with in-lined example code. Since CodeGuide only has minimal support for javadoc, I searched the web for an additional tool that would allow me to visually do the documentation authoring. I stumbled onto this plugin for XMLmind and I must say that it's one of the coolest tools I've used in a long time. It fully preserves your java code formatting and you're even able to use spellchecking inside the javadoc comments!
Here's the obligatory screenshot:
