@jira metadoc
I've just started a small bit of meta-data experimentation, now - whenever working on an issue in our Jira database, I appended to the JavaDoc of any method I touch with "@jira ISSUE-###", I've got a few wee plans in the back of my head for using this in JavaDoc generation ( linking to the Jira issues ), and also an IDEA plugin for tracking what code was changed as a result of an issue.
In the current project I'm working on, which was the result of some outsourcing, I found roughly 50 methods being touched by moving one field from one table to another, to me - this is effectively highlighting the evil evil code smell that is left in this project ( built with some attrocity called Low Road ).
I'm thinking of some of the nifty things that could be done with this in combination with the new attributes metadata spec, instead of just throwing a simple stack trace or error message, if the method has a jira issue attached to it, it could be reported along with the exception for possible related problems. Mmmmmmm.