Showing related articles in a WordPress blog

A few days ago I made a small change to the site. On pages showing a single article, the sidebar now shows a list of related articles on the site. By exposing these articles I hope visitors will find other interesting stuff to explore on this site.

The WordPress plugins to add related articles I found seemed a bit to complex to me, so I was glad I found some PHP code to do the same. This code looks for other articles with the same tags as the displayed article. I changed it a bit into a separate part that retrieves the articles and a part to display them.

The only thing I need to do now is to tag all the older articles, since I only started tagging recently.