Creating a "tag" system to find relevant "related" pages

Hello,

I'm wondering what everyone's opinion is on what would be the best way to implement comma-separated tags on a web site using PHP, MySQL, and Javascript. Each page should have tags which are created along with the page that describe the content on that page. I want to compare tags between pages to find the most relevant "related" pages on my site.

In case that isn't clear, what I am trying to explain would be very similar to the comma-separated "Tags" field just below this text box on the forum where "you may add 5 tag(s) to this thread."

What is the best way to implement this? Does anyone have a script that might get me started? Thanks in advance.

Sorry, what are the Tags for? I mean what is the purpose?
Cheers...

The tags will be for showing "related pages," more specifically for determining whether or not the pages are actually related. At the bottom of each article displayed on my site, I would like to display a "related articles" section that shows links to 5 related articles determined by tags.

The article author will add tags to the article when it is created. on the .PHP page for an article, I would place code at the bottom that generates the list of links based on the tag algorithm that determines the 5 most relevant articles. I can think of a few different ways to do it, but I know there must be a lot of scripts out there that do already do this... so rather than trying to reinvent the wheel from scratch I thought I'd ask you guys for some suggestions. Thanks a lot for your reply!

Lots of ways depending on exactly what you're after.

A simple method is to store all content for pages in a database. When the data gets added, run a script that counts which words/phrases occurs most often and store the top five in a separate field in the database, comma separated.

This then gets listed with each article, and turn each word into a key link. This then does a search and finds other articles in the database that have keywords in common.

That's just one of many possible ways of doing something along these lines...

Dan