To use this code, you'll need to do the following:

1. Replace the entries in $images with your own in the rotate.php file.
   
2. Upload all files
   or copy the index.php code into the page you want, e.g.

   <img src='rotate.php?i=0'>image #1
   <img src='rotate.php?i=1'>image #2
   <img src='rotate.php?i=2'>image #3
   and so on...
   
   and upload rotate.php and images into the same directory as the page you are working on

3. (OPTIONAL) Change the $secondsFixed to decide for how long the list will stay the same before it's reordered. The timeframe should be large enough to allow all the PHP calls to be made easily within the time allotted.
   One note: setting the $secondsFixed value to 10 ensures that the random list reorders every ten seconds. So, if the PHP calls for a page straddle this boundary -- some within a ten second boundary, some outside it -- the list could still be poorly randomized. To avoid this, you can increase the value. For instance, at 3600, the list will stay the same for an hour, and it's the rare page load that will cross that boundary exactly.

Aside from that small hitch, this is a useful PHP technique that allows me to show a randomly-selected series of images without duplicates. I've already placed it successfully on one of my sites, as well as a client's eBay auction (to 'freshen' the display from time to time). I hope it can prove useful to you as well.