
This script takes an inventory of all image files in a directory and displays one at random. All you need to do is save this code in a directory that contains your images (name it what you will, but make sure it has a ".php" extension). Then just link to this script to get your random image.
I would recommend naming this file "index.php," and then you can just link to the directory itself.
I use this file to rotate though a dozen different header pictures.
See a live preview here Keep refreshing the page, you'll notice the graphic at the top changes. But don't limit yourself, have a lot of sigs you like but don't want your signature to seem to obnoxious? Use this to rotate between them!