[ed note: Paul was quick to follow my suggestion in Part 1 and has already moved and categorized many of the older Board Meeting pages. Now to find a new example...]
Start on any Fedora Project wiki page such as https://fedoraproject.org/wiki/
Look at the menus on the left at the "Toolbox" near the bottom.
Click on "Special pages"
Lets begin in the second section which is titled "List of pages"* All pages - allows you list all pages beginning with a specific string. It defaults to the main space but can also be used to find pages in other namespaces.
Example: Looking at pages that begin with "bug" shows all the BugZappers/Meetings/* files that can be moved to the Meeting namespace. The directory hierarchy style of naming in a carry over from the old wiki system and is not recommended in the current mediawiki environment. So these files should also be renamed to something more like "Bugzappers meeting minutes $date" and placed into a category such as "Bugzappers meetings". Another large example would be pages that start with Extras. Since Extras is from Fedora Core days, I would guess that many of these pages can be archived or renamed.
Warning: All pages will list redirect pages as well as pages with content. For example, listing all pages that start with Docs/Beats also shows many pages. However, follow one of the links and you will find that these pages have already been renamed to Documentation Beats. [Look below the (new) title and above the banner image where is says "redirected from" - the URL will not change (yet)]. This is an example of why it is more useful for members of a team to move their own pages rather than the wiki team trying to keep track of everything.
Example: There was already a "Board meetings logs" category and now there is also a "Board meetings" category. Docs Project has categories "Docs Project meetings" and Docs Project meeting logs" and "Docs Project archives" and several others.
The last two options that I find particularly useful to the wiki cleanup project are from the top section titled "Maintenance reports" and are