JUnit Doclet and Code that documents itself.
JUnitDoclet looks kinda cool - found via James Strachan. It generates skeletons of TestCases based on your application source code. And it supports you to reorganize tests during refactoring. Nice - maybe we should use this on Roller and see if we can learn anything.
One thing we were discussing on the roller-development list today was if it's possible to generate generate documentation straight from our javadocs. I'd like to see something similar to javadocs, but easier for the non-programmer types to use and understand.