title: How would you implement a category structure like dmoz.org
body: <p>I don't have a problem with building the category structure. I have a problem trying to figure out how they included similar or other categories similar to a given one. For example, if you choose the "computers / software" category you will see a category for consumer information, games, sports, home etc. These categories don't belong directly under the software category, yet they are similar.</p>
  
  <p>How would you implement something like this?</p>