PHP anti leaching

Does anyone know of a way to stop image leachers from directly linking to images on your site using PHP?

I thought perhaps a scrambling code to protect the source (javascript and php), and a transparent gif overlayed on a table where the image is the background? Anyway, if anyone knows of a good scrambling code or a way to set image protection without making changes to server settings… please let me know!

After much hunting on the web I’ve found a tut that deals with it solely in php.

basically its:

<img src="readimage.php?path=images/img.jpg">

where the path is passed to another php script and modified to protect the images full path.

pretty cool man