yeah.. basically you add a small script on your site so if someone tries to hotlink any of your images, you can make it so they get another image instead - like
this (I found that one on google).
Here's a site with a tutorial and code
http://altlab.com/htaccess_tutorial.html
I don't have a page of my own, so I don't know much more about it. I've just seen others use it. It seems to work pretty well though
