Nice contribution, Denny :)

Here's a few quick comments:

-JavaWoman has some doubts about using UNION - not all versions of MySQL support it; we support 3.23 and higher.
- For record counting, you might use the new getCount() method available as a beta on this server: see WikkaCountingRecords.
- There are some minor issues with the CSS, like the table borders that look a little weird. Also consider that we should try to define a consistent layout for all data tables and avoid creating a lot of specific classes for specific actions/handlers if possible.
- You might also want to add column headings, take a look at http://wikka.jsnx.com/MediaWikiComparison to see the kind of layout and structure we would like to adopt for data tables.

Good job!

Also, consider that with minor changes in the code, the same page-related functionality can be easily adapted to be used either as action or as a handler: there are cases in which a handler (which provides on-the-fly, invisible services) makes more sense than an action (which provides content or services embedded in the page body) and viceversa. An example of this double use is the /backlinks handler that provides the same functionality as the {{backlinks}} action, but spares you from adding the action to a page and previewing it if what you need is only a quick look to some page statistics. Obviously, deciding the best flavour for page-related functionality (action vs. handler) is a matter of taste and needs of the wiki administrator.