Sorry for the delay!

Lunch break and then took forever to write this!
Here's the script:
Code:
<?
$randomNum = rand (1,3);
$img1 = "sponsor1.jpg";
$img2 = "sponsor2.jpg";
$img3 = "sponsor3.jpg";
$image = ${'img'.$randomNum};
Print "<img src=".$image.">";
?>
Working here:
http://www.freepr0nz.com/gfy/test.php
I didn't create this, my bf got it somewhere but it's quite easy to customize which is great

you can use it even to rotate banners or I'm using it to show different POTDs of different sites in my blog (that just went down due to a GoDaddy fuckup! redirecting to plesk? WTF!)
You can add more fields and more images and whatnot

To add more pictures just add additional "$img#" rows and change the number in the "rand (1,3)" bit for the number you have available
I also have one that when you hover goes through the pictures (think the preview function on Redtube) Code for that:
Code:
<html>
<head>
<script type='text/javascript' src='thumbchange.js'>
</script>
</head>
<body>
<script type='text/javascript'>
stat['sponsor1']=0; pic['sponsor1']=new Array(); pics['sponsor1']=new Array(1,1,1);</script>
<a href="niche.html"><img id="sponsor1" src="sponsor1_001.jpg" onmouseout='endm("sponsor1"); this.src="sponsor1_001.jpg"; ' onmouseover='startm("sponsor1","sponsor1_",".jpg"); '></a>
</body>
</html>
Repeat the bit within the body for every niche

- the part that says (1,1,1) has to be extended to the amount of pics you have for said sponsor... you can see a working sample here:
http://www.freepr0nz.com/gfy/hover/
And you can download the .js here:
http://www.freepr0nz.com/gfy/hover/thumbchange.js

cheers!