Tired of direct linkers? This code will make it so anyone who direct links from you will get a red X on their site where your image is supposed to be. Copy and paste this code into Notepad, change the part that says yoursite.com, save it as .htaccess, and upload it to your site. You'll need to be hosted or have a domain for it to work.
RewriteEngine on RewriteCond %{HTTP_REFERER} !^$ RewriteCond %{HTTP_REFERER} !^http://(www\.)?YOURSITE.COM/.*$ [NC] RewriteRule \.(gif|jpg)$ - [F]

If this helped, a link back is required.