Here's how you can display a random link or text from a text file.

Create a new file called random.php. Copy this code into it and save it. This is the script that will retrieve a random entry from random.txt.

<? $textfile ="random.txt"; $items = file("$textfile"); $item = rand(0, sizeof($items)-1); echo $items[$item]; ?>

Now you've got to create another new file, this time a text file. This is where you enter the links (as HTML) or text, make sure each entry is on its own line. Save it as random.txt

Use this code where you want the random event to appear:
<? include 'http://www.YOURSITE.com/random.php' ?>

That's it.