In case others want the code, this is it:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^
http://(www\.)?dvtimes.com/.*$ [NC]
RewriteRule \.(gif|jpg)$
http://www.dvtimes.com/nasty.gif [R,L]
Then save as .htaccess
Chance dvtimes to your site name, and add your own pic, save as nasty.gif