User blog comment:Brandon Rhea/Tips for becoming an admin/@comment-168424-20121218010231/@comment-452-20121221195229

I got the idea from the Muppet wiki: http://muppet.wikia.com/wiki/Category:Active_Talk_Pages (Other wikis have the same thing, but the Muppet wiki's page was created in 2005 by User:Toughpigs, and so appears to predate all others, who must have plagiarised the page from the muppet wiki without attribution.)

The easiest way to do it is to add a template to talk pages individually, and have that template add the talk pages to a category, such as Category:Active Talk Pages

A more advanced way is to use DPL, and there are two different ways that could be done:
 * Using a template with a "topic" parameter, and DPL is used to list all template usages, with the topic listed
 * No template, just a DPL list of recently edited talk pages.

I use both DPL methods, so no talk pages are accidentally forgotten if the template isn't used.

The Muppet wiki has a list on the page I linked, but they don't have a topic parameter.