RewriteEngine On
RewriteCond %{REQUEST_FILENAME} .*jpg$ [NC]
RewriteCond %{HTTP_REFERER} !^$ 
RewriteCond %{HTTP_REFERER} !azurs\.net [NC]
RewriteCond %{HTTP_REFERER} !google\. [NC]
RewriteCond %{HTTP_REFERER} !yahoo\. [NC]
RewriteCond %{HTTP_REFERER} !recherche\.aol\. [NC]
RewriteCond %{HTTP_REFERER} !aolrecherche\. [NC]
RewriteCond %{HTTP_REFERER} !alltheweb\. [NC]
RewriteCond %{HTTP_REFERER} !bloglines\. [NC]
RewriteCond %{HTTP_REFERER} !feedshow\. [NC]
RewriteCond %{HTTP_REFERER} !netvibes\. [NC]
RewriteCond %{HTTP_REFERER} !sonicwall\.com [NC]
RewriteCond %{HTTP_REFERER} !newsgator\.com [NC]
RewriteCond %{HTTP_REFERER} !search\?q=cache [NC]
RewriteRule (.*) /watermark4.php?pic=$1