Introducing an utterly unglamourous plugin – the "Properties Manager". This allows you to browse and edit the propertyset on most jira "entities". Depending on the amount of additional work you are willing to put in, this could be a partial solution to JRA-1991 and JRA-2980.
It's probably best to describe this by way of a few examples. Say you wanted to assign a cost centre to each project. Using this plugin you could export the list of projects, then add the cost center column, then import. Why is this useful? You could then display it on a custom field for each issue in this project (when the custom field is available), or query for all projects with this cost centre (when the searcher is available).
Updating all the cost centers manually using this method would be laborious, so now click the link "Export properties for all Project(s)", and edit the CSV file:
Save the file, click on Import Properties, enter the path to the CSV file, and click Import:
A use for this right now can be found in conjunction with the Behaviours plugin, for instance after choosing a project or component the help text could display the relevant cost centre:
Another example might be to display the reporter's phone number on the issue, which could be done using the "user property" custom field in the JIRA Toolkit.
In general, I can see this being useful for integrations with other systems, where you might need to add additional metadata to JIRA entities such as Versions, Projects, Users and so on.
This has been tested with jira 3.13.5 and 4.0.1… other versions should work as well.
This plugin is written in groovy, so you need the groovy runtime downloadable from here. Copy the file groovy-n-n-n.jar from the embeddable directory to WEB-INF/lib. This was written with groovy 1.7.1, earlier versions should work but haven't been tested.
Download the propertyadmin-10.jar and also copy to WEB-INF/lib.
Alternatively build the jar from source using "atlas-mvn package".
The property admin tool is available from Administration, in the "Import & Export" section.
Importing properties from a spreadsheet is good for one-off bulk imports, or initial setup of the system, however for keeping JIRA properties synchronised you'd probably want to use a web service.
Searching – you need to be able to search on properties, eg all open issues in a project with a particular cost centre. When I get round to this it will most likely be JQL only.
More custom field types – at the moment there is only a "user property" custom field courtesy of jira toolkit. I'll probably add version, project etc custom fields.